What is the Latin word for unpremeditated?

The usual Latin words for “unpremeditated” are subeō, incōgĭtātus. The right choice depends on the sense; see the distinctions below.

English → Latin

“unpremeditated” in Latin

subeōto go under, come under; enter; to come or go up to, approach, draw near, advance or proceed to a place; come or go on; incōgĭtātusunconsidered

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

unpremeditated

subitus (sudden, made on the spur of the moment): incogitatus (Sen.): *non cogitatus. An unpremeditated speech, oratio subita or subita et fortuita (opposed to commentatio et cogitatio).

Quick answer

What is the Latin word for unpremeditated?: The usual Latin words for “unpremeditated” are subeō, incōgĭtātus. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.