OK

Synonyms: All right, right then, very well, very good, agreed, oke, okey-doke, righto, right, right you are, yes, fine, achcha, okey-dokey, roger, and righty-ho.

Synonyms: Satisfactory, fine, acceptable, up to the mark, up to par, adequate, passable, quite good, decent, average, moderate, unexceptional, so-so, (plain) vanilla, jake, all right, in order, up to scratch, up to standard, competent, tolerable, reasonable, fair, not bad, middling, unremarkable, hunky-dory, fair-to-middling, and tickety-boo.

Synonyms: Fine, well, in good health, healthy, as fit as a flea, up to snuff, as right as a trivet, all right, in good shape, fit, as fit as a fiddle, in fine fettle, and in the pink.

Synonyms: Permissible, acceptable, in order, fine, suitable, allowable, all right, permitted, fitting, and appropriate.

Synonyms: All right, well, satisfactorily, tolerably, fine, well enough, passably, and acceptably.

Synonyms: Authorization, seal of approval, consent, permission, ratification, approbation, confirmation, leave, the go-ahead, the thumbs up, approval, agreement, assent, endorsement, sanction, acquiescence, blessing, imprimatur, the green light, and say-so.

Synonyms: Authorize, agree to, sanction, ratify, allow, say yes to, give something one's approval, rubber-stamp, give something the green light, give something one's say-so, approve, consent to, pass, endorse, give something one's consent, accede to, give something the nod, give something the go-ahead, and give something the thumbs up.