aspirin

UK: /ˈæspɪrɪn/ US: /ˈæspərɪn, -prɪn/ ,(as′pər in, -prin)

Inflections of 'aspirin' (n):

aspirin

npl

aspirins

npl

WordReference Random House Learner's Dictionary of American English © 2026

as•pi•rin /ˈæspərɪn, -prɪn/   n., pl. -rin, -rins. 

1. Drugs [uncountable] a white substance made from salicylic acid and used to relieve pain and fever;
   acetylsalicylic acid.
2. Drugs a tablet of aspirin:
   [countable] Take an aspirin.

WordReference Random House Unabridged Dictionary of American English © 2026

as•pi•rin  (as′pər in, -prin), n., pl. -rin, -rins. 

1. Drugs [Pharm.] a white, crystalline substance, C₉H₈O₄, derivative of salicylic acid, used as an anti-inflammatory agent and to relieve the pain of headache, rheumatism, gout, neuralgia, etc.;
   acetylsalicylic acid.
2. Drugs an aspirin tablet:
   I took two aspirin and went right to bed.

• origin, originally German trademark, equivalent. to A(cetyl) acetyl + Spir(säure) salicylic acid (see spiraea) + -in -in² 1899

Collins Concise English Dictionary © HarperCollins Publishers::

aspirin / ˈæsprɪn/ noun ( -rin, -rins)

1. a white crystalline compound widely used in the form of tablets to relieve pain and fever, to reduce inflammation, and to prevent strokes. Formula: CH₃COOC₆H₄COOH
   Chemical name: acetylsalicylic acid
2. a tablet of aspirin

Etymology: 19th Century: from German, from A(cetyl) + Spir(säure) spiraeic acid (modern salicylic acid) + -in; see also spiraea