'Sentence' is Latin for 'an expressed opinion' — from 'sentire' (to feel). Verdicts and grammar from one root.
A set of words that is complete in itself, typically containing a subject and predicate; a judicial punishment fixed by a court; (verb) to declare the punishment of an offender.
From Old French 'sentence' (opinion, judgment, decision, maxim), from Latin 'sententia' (a way of thinking, an opinion, a feeling, a judicial verdict, a maxim). 'Sententia' is derived from 'sentīre' (to feel, perceive, think), from PIE *sent- (to head for, to feel one's way). A 'sententia' was originally a formulated feeling or opinion — what one 'feels' to be true
The grammatical and legal meanings of 'sentence' seem unrelated but share a common ancestor. A Latin 'sententia' was a considered opinion or judgment. When a judge pronounced a 'sententia,' it was a judicial sentence. When a rhetorician crafted a 'sententia,' it was a pithy saying — a complete