acid
UK[ˈæsɪd]US[ˈæsɪd]
n
A chemical substance that has a pH of less than 7, reacts with metals and bases, and typically has a sour taste.
adj
Having the properties of an acid; sharp-tasting or sour.
adj
(of a remark or tone) Bitter or cutting.
Etymology
The word 'acid' entered English in the early 17th century from the French 'acide', which itself derived from the Latin 'acidus', meaning 'sour' or 'sharp-tasting'. This Latin term is directly related to the verb 'acere', 'to be sour'. The root traces further back to the Proto-Indo-European (PIE) root ak-, meaning 'sharp' or 'pointed', which also gave rise to words like 'acrid', 'acumen', and 'acute'. The semantic journey from the physical sensation of sharpness or sourness to the modern chemical definition reflects the property of acids to produce a sharp taste and their reactive, 'sharp' or corrosive nature.
Analysis
The word 'acid' is a simplex loanword from Latin. It cannot be meaningfully segmented into smaller, independent morphemes using its modern English spelling.
Examples
The scientist carefully poured the acid into the beaker.
Vinegar has a distinctly acid flavor.
His acid comments left everyone in the room feeling uncomfortable.