Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “acid”

acid

noun uk   /ˈæs.ɪd/ us  

acid noun (CHEMICAL)

B2 [C or U] any of various usually liquid substances that can react with and sometimes dissolve other materials: acetic/hydrochloric/lactic acid Vinegar is an acid.Types of chemicalSpecific chemicals, chemical compounds and gasesSubstances and structures in the body

acid noun (DRUG)

[U] slang for LSD (= an illegal drug that makes people see things that do not exist)Specific types of drugDrugs - general wordsSpecific medicines and drugs

acid

adjective uk   /ˈæs.ɪd/ us  

acid adjective (CHEMICAL)

(also acidic) containing acid, or having similar qualities to an acid: an acid taste/smell acid soilFlavours and tastesThe state of matter

acid adjective (UNKIND)

describes a remark or way of speaking that is cruel or criticizes something in an unkind way: her acid wit When she spoke her tone was acid.Ways of speakingDisapproving and criticizingDamaging reputationUnkind, cruel and unfeelingViolent or aggressiveTreating people or animals badlyInsults and abuse
(Definition of acid from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of acid?
Browse related topics

You are looking at an entry to do with Specific types of drug, but you might be interested in these topics from the Drugs topic area:

Add Cambridge dictionaries to your browser to your website

Definitions of “acid” in other dictionaries

Word of the Day

aptitude

a natural ability or skill

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More