- 1[transitive, intransitive] arch (something) if you arch part of your body, or if it arches, it moves and forms a curved shape The cat arched its back and hissed.
- 2[intransitive] to be in a curved line or shape across or over something Tall trees arched over the path.
NAmE//ɑrtʃ//Verb Forms present simple I / you / we / they arch
he / she / it arches
past simple arched
-ing form arching