acid

Meanings

1. 1nouncountable or uncountablechemistry

   A chemical substance that typically tastes sour, turns litmus red, reacts with a base, and has a pH below 7.

   Grammar: Use an acid for one kind, and acid for the substance generally: hydrochloric acid.

   Patterns

   • a strong acid
   • acid reacts with a base
   • dilute the acid

   Vinegar contains acetic acid.

   The technician wore gloves before handling the acid.

2. 2noununcountableinformalslang

   A slang name for the drug LSD, a powerful hallucinogen.

   Grammar: No plural in this drug sense; it is informal rather than scientific.

   Patterns

   • take acid
   • a tab of acid

   The counselor warned that acid can cause frightening experiences.

   In the novel, a character recalls taking acid at a concert.

3. 3adjectivecomparable

   Having a sour taste like lemon juice or vinegar.

   Grammar: Comparable: one lemon can be more acid than another, though acidic is more common.

   Patterns

   • acid fruit
   • an acid flavor

   The dressing tasted too acid, so she added honey.

   Rhubarb has a pleasantly sharp, acid flavor when cooked.

4. 4adjectivecomparablefigurative

   Sharp, biting, or bitter in tone, criticism, or humor.

   Grammar: Usually before a noun or after linking verbs in figurative comments.

   Patterns

   • acid remark
   • acid tone
   • acid wit

   Her acid reply ended the discussion.

   The review was full of acid wit about the plot.

Common combinations

strong acid

A strong acid must be stored in a labeled bottle.

acid rain

Acid rain can damage statues and forests.

acid test

The final interview was the acid test of her confidence.

acid remark

He made an acid remark about the delayed report.

Synonyms and how they differ

sour

Sour describes taste; acid is the chemistry term and can also describe a sharp manner.

caustic

Caustic fits harsh remarks better than chemistry, though caustic substances burn chemically.

LSD

LSD is the precise drug name; acid is the informal street term.

Opposites

Word family

acidic adjective

Common everyday and scientific adjective for sour or low-pH conditions.

acidity noun

The level or quality of being acid.

acidify verb

To make or become acid.

acidly adverb

In a sharp, bitter way, especially of speech.

Commonly confused: acid or acidic? acid or bitter?

Practice

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