Definition
(Verb) To reason; to carry out or form judgements by a process of logical reasoning.
In Context
“In any rigorous or narrow sense the voters are not highly rational; that is, most of them do not ratiocinate on the matter, e.g., to the extent that they do on the purchase of a car or a home.”
Peter Bachrach, Editor, Political Elites in a Democracy, 1971.