Lexical Definition

‎προθέσμιος‎ prothésmios (proth-es'-mee-os) set time ^G:N-F
from ‎πρό‎ and a derivative of ‎τίθημι‎

time appointed.

• fixed beforehand, i.e. (feminine with ‎ἡμέρα‎ implied) a designated day

Abbott-Smith

** 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.†

Abbott-Smith References

Liddell-Scott-Jones

προθεσμία-ία

(i.e. ἡμέρα), ἡ, day appointed beforehand, a fixed or limited time, within which money was to be paid, actions brought, claims made, elections held, etc., and if this period was allowed to expire, no further proceedings were allowed, [Refs 4th c.BC+]; ἐὰν ἡ π. ἐξήκῃ is past, [Refs 5th c.BC+]

__2 generally, fixed or appointed time, προθεσμίαίας οὔσης τῷ κινδύνῳ [προθεσμίαίας ὀλίγης εἰς τὴν χειροτονίαν οὔσης 2nd c.AD: Appianus Historicus “Bella Civilia” 1.14, cf. NT.Gal.4.2, “OGI” 509.21 (Aphrodisias, 2nd c.AD)">NT+5th c.BC+]; οὐκ ἐτήρησε τὴν π. τῆς θεοῦ [Refs 2nd c.AD+]; π. φυσικὴ [νόσου] natural period, [προθεσμίαίας ὁριζομένους ἑορτάς 2nd c.AD: Lucianus Sophista “Nigr.” 27. ">Refs 1st c.AD+]
__3 occasion of delay, [Refs 1st c.AD+]
__II προθέσμιος, α, ον, adjective foreappointed, Ἔφεσος, ἡ π. τῶν γάμων (i.e. πόλις) [Refs]

_{LSJ Scripture Refs: Gal.4.2}