1

acid

noun
Updated on: 15 Nov 2017

Definition of acid

1 :a sour substance; specifically :any of various typically water-soluble and sour compounds that in solution are capable of reacting with a base (see 1base 7a) to form a salt, redden litmus, and have a pH less than 7, that are hydrogen-containing molecules or ions able to give up a proton to a base, or that are substances able to accept an unshared pair of electrons from a base
2 :something incisive, biting, or sarcastic
  • a social satire dripping with acid
3 :lsd

acidy

\ˈa-sə-dē\ adjective

Examples of acid in a Sentence

  1. the acids in your stomach

  2. the kinds of acid found in your stomach

Recent Examples of acid from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'acid.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of acid

borrowed from Medieval Latin acidum, going back to Latin, neuter of acidus 2acid

Other Chemical Engineering Terms


2

acid

adjective ac·id \ ˈa-səd \

Definition of acid

1 a :sour, sharp, or biting to the taste
  • an acid flavor
b :sharp, biting, or sour in manner, disposition, or nature
  • an acid individual
  • an acid personality
c :sharply clear, discerning, or pointed
  • an acid wit
  • acid criticism
d :piercingly intense and often jarring
  • acid yellow
2 a :of, relating to, or being an acid; also :having the reactions or characteristics of an acid
  • acid soil
  • an acid solution
b of salts and esters :derived by partial exchange of replaceable hydrogen
  • acid sodium carbonate NaHCO3
c :containing or involving the use of an acid (as in manufacture)
  • an acid bath
d :marked by or resulting from an abnormally high concentration of acid
  • acid indigestion
3 :relating to or made by a process in which the furnace is lined with acidic material and an acidic slag is used
  • acid steel
4 :rich in silica
  • acid rocks

acidly

adverb

acidness

noun

Examples of acid in a Sentence

  1. He washes his windows with an acid solution of vinegar and water.

  2. with her acid personality, my aunt could be relied upon to bring some much-needed balance to the holiday gush

Recent Examples of acid from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'acid.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of acid

borrowed from French & Latin; French acide, going back to Middle French, borrowed from Latin acidus, adjective derivative from the base of acēre "to be sour" — more at acetic acid

Other Chemical Engineering Terms



ACID Defined for English Language Learners

acid

adjective

Definition of acid for English Language Learners

  • : of, relating to, or having the qualities of an acid

  • : sharp, strong, and critical in tone


acid

noun

Definition of acid for English Language Learners

  • chemistry : a chemical with a sour taste that forms a salt when mixed with a base


ACID Defined for Kids

1

acid

adjective ac·id \ ˈa-səd \

Definition of acid for Students

1 :having a taste that is sour, bitter, or stinging
2 :harsh or critical in tone
  • acid remarks
3 :of, relating to, or like an acid
  • an acid solution

acidly

adverb
  • spoke acidly

2

acid

noun

Definition of acid for Students

:a chemical compound that tastes sour and forms a water solution which turns blue litmus paper red

Medical Dictionary

1

acid

adjective ac·id \ ˈas-əd \

medical Definition of acid

1 :sour, sharp, or biting to the taste
2 a :of, relating to, or being an acid; also :having the reactions or characteristics of an acid
  • an acid solution
b of salts and esters :derived by partial exchange of replaceable hydrogen
  • acid sodium carbonate NaHCO3
c :marked by or resulting from an abnormally high concentration of acid
  • acid indigestion
not used technically

2

acid

noun

medical Definition of acid

1 :a sour substance; specifically :any of various typically water-soluble and sour compounds that in solution are capable of reacting with a base to form a salt, that redden litmus, that have a pH less than 7, and that are hydrogen-containing molecules or ions able to give up a proton to a base or are substances able to accept an unshared pair of electrons from a base
2 :lsd


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