acrid

the word 'acrid' entered english in the early 18th century, derived from the latin root acer (sharp, pungent), which itself can be traced back to the proto-indo-european root ak-, meaning 'sharp' or 'pointed'. this root is the source for many words related to sharpness, such as 'acid' and 'acute'. the latin adjective acer took the form acr- in compounds, which combined with the adjectival suffix '-id' to form a word literally meaning 'having a sharp quality'. over time, the meaning evolved from a purely physical sharpness to describe primarily a sharp, irritating bitterness in smell or taste, and later extended metaphorically to describe harsh, caustic speech or criticism.

Structure: acr (sharp) + id (adjective suffix) acr (from latin acer, acr-, meaning sharp, pungent); id (a suffix of latin origin used to form adjectives, often meaning 'pertaining to' or 'having the nature of').