acidic

acidic — adjective

1. Describes a liquid, soil, or other substance that has acid in it, or that behave

1.adjectiveC1
Definition

Describes a liquid, soil, or other substance that has acid in it, or that behaves like an acid in chemical tests — usually with a pH measurement below 7.

Example

Blueberries grow well in acidic soil with a pH of about 5.

collocation: acidic soil

Dr. Diego warned the class that lemon juice is highly acidic and can damage tooth enamel.

pattern: highly/strongly acidic

Common collocations
  • acidic soil
  • acidic rain
  • acidic solution
  • highly acidic
  • mildly acidic
  • acidic environment
Synonyms
  • acid

    used as an adjective in fixed terms (acid rain, acid soil); 'acidic' is preferred for general descriptions

  • acidulous

    rare and formal; mostly literary or technical

Antonyms
  • alkaline

    the opposite end of the pH scale (above 7)

  • basic

    scientific synonym of alkaline; common in chemistry classes

  • neutral

    neither acidic nor alkaline; pH around 7

Usage Note

Often modified by degree adverbs such as 'highly', 'strongly', 'mildly', or 'slightly'. Distinguish from sense 2 by context: this sense is about chemical content (pH), while sense 2 is about taste sensation.

Common Mistakes

The pH of the lake is 8, so it is acidic.
The pH of the lake is 8, so it is alkaline.
pH below 7 is acidic; pH above 7 is alkaline.
an acid soil' (in a scientific context).
an acidic soil.
when describing the property, use 'acidic'; 'acid' as an adjective is more common in fixed terms like 'acid rain'.

2. Describes a food or drink that has a strong sour, sharp flavour on the tongue —

2.adjectiveC1
Definition

Describes a food or drink that has a strong sour, sharp flavour on the tongue — like a lemon, an unripe fruit, or a vinegary sauce.

Example

Esme pulled a face after one sip of the acidic green wine.

describing wine flavour

The mango was still green and unpleasantly acidic.

Common collocations
  • acidic taste
  • acidic flavour
  • acidic wine
  • acidic fruit
  • too acidic
  • unpleasantly acidic
Synonyms
  • sour

    everyday word; less intense and less formal than 'acidic'

  • tart

    pleasantly sharp, often of fruit or pastry

  • sharp

    general; can mean strong-tasting in many ways, not only sour

  • tangy

    positive: a pleasant, lively sourness

Antonyms
  • sweet

    the opposite taste; sugar-like

  • mellow

    soft and well-rounded, with no sharp edge

Usage Note

Subject is usually a food, drink, or fruit. Distinguish from sense 1: here the speaker is judging taste, not measuring chemistry. Often paired with 'too' or 'unpleasantly' to suggest the sourness is uncomfortable.

Common Mistakes

The candy is acidic and sweet.
The candy is sour and sweet.
for everyday taste, 'sour' is more natural; 'acidic' suggests a sharper, almost chemical sourness.
The orange juice is acid.
The orange juice is acidic.
to describe a sour-sharp taste, the adjective is 'acidic', not 'acid'.

Word family

  • acid
    nounB2
  • acid
    adjectiveB2
  • acidity
    nounC1
  • acidify
    verbC2
  • acidification
    nounC2

Synonym discussion

Sense: adjective/2

All four words describe a sharp, non-sweet taste, but they differ in intensity and feeling. 'Sour' is the everyday word — neutral, used for anything from yogurt to lemons. 'Acidic' is stronger and a little more formal; it suggests the sourness is so sharp it almost feels chemical, and it's the word reviewers use for wine or coffee that has gone past pleasant. 'Tart' usually carries a positive note — a clean, pleasant sharpness, as in a tart cherry pie or a tart green apple. 'Tangy' is the most positive of the four: a lively, mouth-watering sourness that makes a sauce or drink exciting. Compare: 'The yogurt is sour' (a fact), 'The yogurt is tangy' (a compliment), 'The yogurt is acidic' (probably a complaint).

acidic ↗sour ↗tarttangy

Common collocations

Nouns

  • acidic soil
  • acidic rain
  • acidic solution
  • acidic taste
  • acidic flavour
  • acidic wine
  • acidic fruit
  • acidic environment

Adverbs

  • highly acidic
  • strongly acidic
  • mildly acidic
  • slightly acidic
  • unpleasantly acidic

Phrases

  • become acidic
  • turn acidic
  • too acidic

Etymology

LatinFrenchEnglish

Built in English from the noun 'acid' plus the adjective ending '-ic', meaning 'of or relating to'. The noun 'acid' came into English in the 1600s through French and Latin from the Latin verb 'acere', meaning 'to be sour'. 'Acidic' itself appeared later, in the 1800s, as scientists needed a word to describe substances with acid-like chemical behaviour separately from the noun 'acid'.