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.

acid noun (DRUG)

[U] slang for LSD (= an illegal drug that makes people see things that do not exist)

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 soil

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.
(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

first:

(a person or thing) coming before all others in order, time, amount, quality, or importance

Word of the Day

Countability – grammar codes

by Dom Glennon​​,
November 26, 2014
Advices and informations Have you ever noticed strange codes in square brackets on entries in Cambridge Dictionaries Online and wondered what they mean? These are grammar codes, giving you a brief summary of how that word behaves grammatically. More information can be obtained by hovering your cursor over the code, and there’s

Read More 

ped-text verb

November 24, 2014
to text someone while walking I’m ped-texting, I’m looking down at my phone, 75 percent of the time.

Read More