Abbott-Smith Manual Greek Lexicon
προ-θέσμιος (G4287)
1 ** προ-θέσμιος , -α, -ον , [in Sm.: Jb 28:3 , Da 9:26 *;] appointed beforehand . In Attic law, as subst. (so always in cl.), ἡ π. (sc. ἡμέρα ), a day appointed beforehand , a previously appointed time : Ga 4:2 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain