The Coandă effect icon is the tendency of a fluid

Fluid

In physics, a fluid is a substance that continually deforms under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids....

 jet

Jet (fluid)

A jet is an efflux of fluid that is projected into a surrounding medium, usually from some kind of a nozzle, aperture or orifice. Jets can travel long distances without dissipating...

 to be attracted to a nearby surface. The principle was named after Romanian aerodynamics pioneer Henri Coandă

Henri Coanda

Henri Marie Coandă was a Romanian inventor, aerodynamics pioneer and builder of an experimental aircraft, the Coandă-1910 described by Coandă in the mid-1950s as the world's first jet, a controversial claim disputed by some and supported by others...

, who was the first to recognize the practical application of the phenomenon in aircraft development.
An early description of this phenomenon was provided by Thomas Young

Thomas Young (scientist)

Thomas Young was an English polymath. He is famous for having partly deciphered Egyptian hieroglyphics before Jean-François Champollion eventually expanded on his work...

 in a lecture given to The Royal Society in 1800:

The lateral pressure which urges the flame of a candle towards the
stream of air from a blowpipe is probably exactly similar to that pressure which
eases the inflexion of a current of air near an obstacle.