Answer: lockin

AnswerCrossword Clue
LOCKINGuarantee, as a loan rate
LOCKINFinalize, as a Final Jeopardy! wager
LOCKINCommit unalterably
LOCKINGuarantee, as a mortgage rate
LOCKINEncage: 2 wds.
LOCKINMake permanent
LOCKINEnsure
LOCKINFix permanently, as an interest rate