Butyric \Bu*tyr"ic\, a. (Chem.) Pertaining to, or derived from, butter.

Butyric acid, C3H7.CO2H, an acid found in butter; an oily, limpid fluid, having the smell of rancid butter, and an acrid taste, with a sweetish aftertaste, like that of ether. There are two metameric butyric acids, called in distinction the normal- and iso-butyric acid. The normal butyric acid is the one common in rancid butter.

Source: Webster's Revised Unabridged Dictionary (1913)