Lexical Definition

‎θροέω‎ throéō (thro-eh'-o) to alarm ^G:V
from to wail

trouble.

• to clamor, i.e. (by implication) to frighten

Abbott-Smith

θροέω, -ῶ (< θρόος, a noise, tumult), [in LXX: Ca 5:4 [המה*;] in cl.,
1. to cry aloud, make an outcry.
2. to utter aloud.
3. In NT (and LXX), pass., to be troubled, as by an alarm: Mt 24:6, Mk 13:7, Lk 24:37 (WH, mg.), II Th 2:2 (cf. Kennedy, Sources, 126).†

Abbott-Smith References

Liddell-Scott-Jones

θροέω,

aorist ἐθρόησα, poetry θρο- [Refs 5th c.BC+] — middle and passive (see. below): (θρόος):—cry aloud, [Refs 5th c.BC+]; παρὰ νοῦν θ. [Refs]; πᾶσιν to all, [Refs]; speak, say, [Refs 4th c.BC+]; θρόει, τίς..; [Refs 5th c.BC+]; εὔφημα, ψευδῆ, [Refs 5th c.BC+]:—middle, τοῦτ᾽ ἔπος -ούμενος [Refs 4th c.BC+]

__2 with accusative, tell out, utter aloud, τοὐμὸν πάθος [Refs 5th c.BC+]—Rare. except in Trag.; in late Prose, [Refs 1st c.AD+]
__II causal, scare, terrify, [Refs 5th c.BC+]:—passive, to be stirred. moved, of joy, ἡ κοιλία μου ἐθροήθη ἐπ᾽ αὐτόν [LXX]; of fear, μὴ θροεῖσθε [NT]

_{LSJ Scripture Refs: LXX.Song.5.4 ☩ Matt.24.6 ☩ 2Thess.2.2}