adj. 1
Of two or more things: that cannot coexist; not congruous because of differences; unable to function together due to dissimilarities.
My phone is incompatible with the latest version of this app.
adj. 2
Incapable of being together without mutual reaction or decomposition, as certain medicines.

Related words

Word family: incompatibility incompatibleness incombinable

Choose the right word

Incompatible or Inconsistent?

Incompatible primarily signifies unable to sympathize or feel alike; inconsistent means unable to stand together. Things are incompatible which can not exist together in harmonious relations, and whose action when associated tends to ultimate extinction of one by the other.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

inconsistent Nursery rhymes are deliberately inconsistent texts.
contradictory What they say is contradictory to their feelings.
incongruous He has an incongruous sounding name which is hard to remember.
irreconcilable The two political parties are irreconcilable foes.
antagonistic The two countries are antagonistic to each other.
mismatched Why does Chris wear mismatched socks?

Popularity over time

Word	1850 → 2019	Trend
incompatible		steady
inconsistent		steady
contradictory		rising
incongruous		steady
irreconcilable		steady
antagonistic		steady

Use in printed books, per decade from 1850 to 2019.

By length

7 letters: hostile², jarring²
8 letters: opposite³, contrary³, assorted³, unsuited³, inimical⁴, mismated
9 letters: different³, abhorrent³, repugnant³, dissonant³, unfitting
10 letters: dissimilar⁴, mismatched², discordant³, immiscible⁴, discrepant
11 letters: conflicting³, incongruous⁴, contrastive, uncongenial
12 letters: inconsistent⁴, antagonistic⁵, disagreeable⁵, inharmonious
13 letters: inappropriate⁵, contradictory⁵
14 letters: irreconcilable⁶

The small number after each word is its number of syllables (hostile² = 2 syllables).

In other languages

Français: incompatible
Italiano: incompatibile
Deutsch: inkompatibel