What's the difference between i.e. and e.g.?
1540s, "quality of being acrid," from Middle French acrimonie or directly from Latin acrimonia "sharpness, pungency of taste," figuratively "acrimony, severity, energy," from acer "sharp" (fem. acris, neuter acre; see acrid) + -monia suffix of action, state, condition. Figurative extension to "sharpness of temper" is first recorded 1610s.