- 1[transitive, intransitive] reason (that…) + speech to form a judgment about a situation by considering the facts and using your power to think in a logical way She reasoned that she must have left her bag on the train. They couldn't fire him, he reasoned. He was the only one who knew how the system worked.
- 2[intransitive] to use your power to think and understand the human ability to reason Phrasal Verbsreason something outreason with somebody
NAmE//ˈrizn//Verb Forms present simple I / you / we / they reason
he / she / it reasons
past simple reasoned
-ing form reasoning