adjective
- slightly sour.
- sharp; caustic: his acidulous criticism of the book.
- moderately acid or tart; subacid.
adjective
- rather sour
- sharp or sour in speech, manner, etc; acid
1769, “sub-acidic,” used figuratively for “sour-tempered;” from Latin acidulus “slightly sour,” a diminutive of acidus (see acid (adj.)).
adj.
- Slightly acid or sour.