ratiocinate

verb

ra·​ti·​o·​ci·​nate ˌra-tē-ˈō-sə-ˌnāt 

ˌra-shē-,

-ˈä-

ratiocinated; ratiocinating

intransitive verb

: reason

ratiocinator

ˌra-tē-ˈō-sə-ˌnā-tər 

ˌra-shē-

-ˈä-

noun

Word History

Etymology

Latin ratiocinatus, past participle of ratiocinari to reckon, from ratio + -cinari (as in vaticinari to prophesy) — more at vaticinate

First Known Use

1643, in the meaning defined above