The acetabulum of the pelvic bone, the socket of the ball-and-socket hip joint, is Latin for “little vinegar cup”, deriving from acetum, vinegar.
Given their predilection for vinegar as a condiment, acetabula were no doubt common on the dinner tables of the ancient Romans. The term eventually came to mean any wide mouthed vesicle of varying sizes and uses; acetabula were ultimately seen throughout the Roman Empire.
The term was first used in the anatomical sense by both Celsus and Pliny the Elder, Roman encyclopedists from the 1st century B.C.
An acetabulum from A Dictionary of Greek and Roman Antiquities, by Sir William Smith, 1875.
An acetabulum can be seen on the right hand side of the table in Da Vinci's "The Last Supper", shown here with color added in a close up of a woodcut. That's Matthew, Thaddeus, and Simon, left to right, so the scholars say.
Acetabulum was a Roman unit of measurement as well, equal to about 275 ml (9 fluid oz).
Also from acetum: acetic acid; Vinegar is a solution of around 4% acetic acid