Lexical Definition

‎πράκτωρ‎ práktōr (prak'-tor) bailiff ^G:N-M
from a derivative of ‎πράσσω‎

officer.

• a practiser, i.e. (specially), an official collector

Abbott-Smith

πράκτωρ, -ορος, ὁ (< πράσσω), [in LXX: Is 3:12 (נֹגֵשׂ)*;]
1. (poët.) one who does or accomplishes.
2. In Athens, one who exacts payment, a collector; hence, generally (freq. in π., v. Deiss., BS, 154), a court officer: Lk 12:58.†

Abbott-Smith References

Liddell-Scott-Jones

πράκτωρ-τωρ, ορος, ὁ,

={πρακτήρ}, one who does or executes, accomplisher, Ζεὺς ὅτου π. φανῇ [Refs 5th c.BC+]; with feminine substantive, Κύπρις.. τῶνδ᾽ ἐφάνη π. [Refs 5th c.BC+]

__II official who executes a judgment for debt, especially public debt, bailiff, [NT+5th c.BC+]; τῶν ξενικῶν [Refs 2nd c.BC+]
__II.2 collector of taxes, π. βαλανήου “Ostr.” in Wilcken Grundzüge [Refs 1st c.AD+]; π. ἀργυρικῶν [Refs 2nd c.AD+]; π. σιτικῶν [Refs 2nd c.AD+]
__II.3 in Poets, one who exacts punishment, avenger, [Refs 5th c.BC+]: as adjective, with a feminine substantive, avenging, σὺν δορὶ καὶ χερὶ πράκτωρτορι [Refs 4th c.BC+]

_{LSJ Scripture Refs: Luke.12.58}