acrimony (n.)

1540s, "quality of being sharp or pungent in taste," from Middle French acrimonie or directly from Latin acrimonia "sharpness, pungency of taste," figuratively "acrimony, severity, energy," abstract noun from acer "sharp" (fem. acris), from PIE root *ak- "be sharp, rise (out) to a point, pierce") + -monia suffix of action, state, condition. Figurative extension to personal sharpness or bitterness is by 1610s.