Lexical Definition

‎τρίβολος‎ tríbolos (trib'-ol-os) thistle ^G:N-M
from ‎τρεῖς‎ and ‎βέλος‎

brier, thistle.

• properly, a crow-foot (three-pronged obstruction in war), i.e. (by analogy) a thorny plant (caltrop)

Abbott-Smith

τρίβολος, -ου, ὁ [in LXX: Ge 3:18, Ho 10:8 (דַּרְדַּר), II Ki 12:31 (חָרִיץ), Pr 22:5 (צֵן)* ;]
a thistle: Mt 7:16, He 6:8.†

Abbott-Smith References

Liddell-Scott-Jones

τρίβολος [ῐ], ὁ,

name of various prickly plants,

__a water-chestnut, Trapa natans, τ. ἔνυδρος [Refs 4th c.BC+]
__b caltrops, Tribulus terrestris, [Refs 5th c.BC+]; τ. περικαρπιάκανθος, χερσαῖος, [LXX+7th c.BC+]
__c τ. φυλλάκανθος, thorny trefoil, Fagonia cretica, [Refs 4th c.BC+]
__d τ. παραθαλάσσιος, prickly samphire, Echinophora spinosa, [Refs 5th c.BC+]
__II τρίβολοι, οἱ, a threshing-machine, a board with sharp stones fixed in the bottom, [LXX+3rd c.BC+]; τ. ξύλινος (in the section περὶ κάρρων) [Refs 1st c.AD+]
__III caltrop, i. e. a four-spiked implement thrown on the ground to lame the enemy's horses, [Refs 3rd c.BC+]
__III.b τ. πηχῶν έ a larger contrivance for stopping boulders, etc., thrown down a slope, [Refs 2nd c.BC+]
__III.c οἱ κατακρημνώμενοι τ. an instrument hung from the walls of a fortress as a defence against battering-rams, [Refs 3rd c.BC+]
__III.d a kind of missile, τριβόλων σιδηρῶν σφενδονῆται [Refs 1st c.BC+]; οἱ τ. οἱ καιόμενοι a kind of incendiary missile, [Refs 3rd c.BC+]
__IV part of the bit of a bridle, [Refs 3rd c.BC+]
__V uncertain meaning in naval dockyard records, σίδηρος ἐκ τοῦ τ. [Refs]
__VI as adjective, three-tiered, πυρὰ πυργοειδὴς τ. [Refs 2nd c.AD+]

_{LSJ Scripture Refs: LXX.Gen.3.18 ☩ LXX.2Kgs.12.31}