Carpe diem is a phrase from a Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 poem by Horace

Horace

Quintus Horatius Flaccus , known in the English-speaking world as Horace, was the leading Roman lyric poet during the time of Augustus.-Life:...

 (see "Source" section below) that has become an aphorism

Aphorism

An aphorism is an original thought, spoken or written in a laconic and memorable form.The term was first used in the Aphorisms of Hippocrates...

. It is popularly translated as "seize the day". Carpe literally means "to pick, pluck, pluck off, cull, crop, gather", but Ovid

Ovid

Publius Ovidius Naso , known as Ovid in the English-speaking world, was a Roman poet who is best known as the author of the three major collections of erotic poetry: Heroides, Amores, and Ars Amatoria...

 used the word in the sense of, "to enjoy, seize, use, make use of".
In Horace

Horace

Quintus Horatius Flaccus , known in the English-speaking world as Horace, was the leading Roman lyric poet during the time of Augustus.-Life:...

, the phrase is part of the longer Carpe diem, quam minimum credula postero – "Seize the Day, putting as little trust as possible in the future", and the ode says that the future is unforeseen, and that instead one should scale back one's hopes to a brief future, and drink one's wine.