The loins are the sides between the lower rib

Rib

In vertebrate anatomy, ribs are the long curved bones which form the rib cage. In most vertebrates, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax...

s and pelvis

Pelvis

In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...

, and the lower part of the back

Back

- People :* Adam Back, British cryptographer* Charles Back, South African winemaker* Chris Back , Australian politician* Ernst Emil Alexander Back , German physicist* Frédéric Back , Canadian animator...

. It is often used when describing the anatomy of human

Human

Humans are the only living species in the Homo genus...

s and quadruped

Quadruped

Quadrupedalism is a form of land animal locomotion using four limbs or legs. An animal or machine that usually moves in a quadrupedal manner is known as a quadruped, meaning "four feet"...

s (such as horse

Horse

The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

s, pig

Pig

A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...

s or cattle

Cattle

Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

). The anatomical reference also carries over into the description of cuts of meat from some such animals, eg. tenderloin

Beef tenderloin

A beef tenderloin, known as an eye fillet in New Zealand and Australia, filet in France and Germany and fillet in the United Kingdom, is cut from the loin of beef. As with all quadrupeds, the tenderloin refers to the psoas major muscle ventral to the transverse processes of the lumbar vertebrae,...

 or sirloin steak

Sirloin steak

The sirloin steak is a steak cut from the rear back portion of the animal, continuing off the short loin from which T-bone, porterhouse, and club steaks are cut....

.

Human anatomical term

In human anatomy

Anatomy

Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

 the term "loin" or "loins" refers to the side of the human body below the rib cage

Rib cage

The rib cage is an arrangement of bones in the thorax of animals. It is formed by the vertebral column, ribs and sternum and encloses the heart and lungs....

 to just above the pelvis. It is frequently used to reference the general area below the ribs. While the term "loin" is generally not used in medical science, some disorders do contain it.

The lumbar

Lumbar

In tetrapod anatomy, lumbar is an adjective that means of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum ...

 region of the spinal column is located in the loin area of the body.

The spinal column consists of five regions: cervical, thoracic, lumbar, sacral and coccygeal. That means "lumbar" is the third region.

Euphemism for human genitals

The term also has become euphemistic for human genitals

Sex organ

A sex organ, or primary sexual characteristic, as narrowly defined, is any of the anatomical parts of the body which are involved in sexual reproduction and constitute the reproductive system in a complex organism; flowers are the reproductive organs of flowering plants, cones are the reproductive...

 due to their prominence in that anatomical region. Because of this euphemistic use of the term, the article of clothing

Clothing

Clothing refers to any covering for the human body that is worn. The wearing of clothing is exclusively a human characteristic and is a feature of nearly all human societies...

 that is worn around the genital area has been named a loincloth

Loincloth

A loincloth is a one-piece male garment, sometimes kept in place by a belt, which covers the genitals and, at least partially, the buttocks.-History and types:Loincloths are being and have been worn:*in societies where no other clothing is needed or wanted...

.

In the Authorized King James Version of the Christian Bible the term "loins" is used frequently. It is suggested that the "loins" is the minimum one must cover on their body to be respectful of the law. This suggests that if a man (or, possibly, a woman as well) covers up just their genital area, they are considered clothed enough for public life.
Frequently the expression "fruit of his loins" is used to refer to children.
Such a "fruit of my loins" reference is also made in the King James Version.

It is also used as a term for the general lower area of the body much like the term "below the belt

Below the belt

Mainly used in combat sports such as boxing and kickboxing, below the belt refers to all the area of the body that lies below the line of the opponent's navel, including the genital area, legs, and crotch...

" references the area below where the average person would wear a belt

Belt (clothing)

A belt is a flexible band or strap, typically made of leather or heavy cloth, and worn around the waist. A belt supports trousers or other articles of clothing.-History:...

.

The term "gird one's loins" was used in the Roman Era meaning to pull up and tie one's lower garments between one's legs to increase one's mobility in battle. In the modern age, it has become an idiom

Idiom

Idiom is an expression, word, or phrase that has a figurative meaning that is comprehended in regard to a common use of that expression that is separate from the literal meaning or definition of the words of which it is made...

 meaning to prepare oneself for the worst.

Loins in butchery

Butcher

Butcher

A butcher is a person who may slaughter animals, dress their flesh, sell their meat or any combination of these three tasks. They may prepare standard cuts of meat, poultry, fish and shellfish for sale in retail or wholesale food establishments...

s frequently refer to the section of meat

Meat

Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...

 below the rib cage, but above the round

Round steak

A round steak is a steak from the round primal cut of beef. Specifically, a round steak is the eye round, bottom round, and top round still connected, with or without the "round" bone , and may include the knuckle , depending on how the round is separated from the loin. This is a lean cut and it...

 as loin.
Various names of meats further butchered from the loin section of cattle

Cattle

Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

 and pork

Pork

Pork is the culinary name for meat from the domestic pig , which is eaten in many countries. It is one of the most commonly consumed meats worldwide, with evidence of pig husbandry dating back to 5000 BC....

 contain the name "loin" such as tenderloin

Tenderloin

-Media:* Tenderloin , by Samuel Hopkins Adams* Tenderloin , a 1928 film* Tenderloin , a musical from 1960* "Tenderloin", a song by Rancid from Let's Go...

 and sirloin. In America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

n culinary art

Culinary art

Culinary art is the art of preparing and cooking foods. The word "culinary" is defined as something related to, or connected with, cooking. A culinarion is a person working in the culinary arts. A culinarian working in restaurants is commonly known as a cook or a chef. Culinary artists are...

s the loin section of meat from the top half of cattle is divided into three sections. The various cuts of beef from this section are named sirloin, tenderloin

Tenderloin

-Media:* Tenderloin , by Samuel Hopkins Adams* Tenderloin , a 1928 film* Tenderloin , a musical from 1960* "Tenderloin", a song by Rancid from Let's Go...

, top sirloin, and short loin. They are named for their respective parts on the cattle.

In the British butchery tradition, the same set of muscles are generally referred to as the "rump".

It has been suggested by culinary professionals that tenderloin is the most tender

Tenderness

Tenderness can mean:* a tendency to express warm, compassionate, or affectionate feelings* delicate or intimate physical contact* tenderness – pain or discomfort when an affected area is touched-Other:...

 cut of beef one can get. The loin section of beef is fairly popular among consumers for its low fat qualities. It is the source of filet mignon

Filet mignon

Filet mignon is a steak cut of beef taken from the smaller end of the tenderloin, or psoas major of the beef carcass, usually a steer or heifer...

.