decide, fix, agree upon, appoint
決 centers on making a firm choice or settlement: deciding, fixing, agreeing upon, or appointing something with finality.
to decide; to choose; to determine; to make up one's mind; to resolve; to set one's heart on; to settle; to arrange; to set; to appoint; to fix
decision; determination
settlement; solution; resolution
to be decided; to be settled; to be fixed; to be arranged
(not) ever; (not) by any means; (not) in the least; (not) in any way; (not) at all
judicial decision; judgement; judgment; sentence; decree
decision of a contest; finals (in sports)
rule; regulation
confrontation; showdown
decision; determination
decision; determination; resolution
settlement (of an account); liquidation of debts; payment
conclusion; decision; end; settlement
decisive battle; deciding match; play-off
definite; final; decisive; conclusive
settlement of accounts; closing accounts; financial results; reporting (of accounts)
resolution; vote; decision
approval; adoption (of a motion, bill, etc.); passage
determination; resolution
semifinal
vote; ballot; division
decision; vote
decision; agreement
decider; person who decides
決 combines 氵 (water) with 夬, which likely contributes the sound and the idea of separating or breaking through, suggesting water cutting a channel and thus a decisive action.
Water 氵 flows and cuts a clear path through the right side 夬, like a decision cutting through uncertainty.
For ケツ, imagine a decisive person named Ketsu who always makes quick decisions: Ketsu -> ケツ, and their firm choice is like water cutting a channel.