Easton's Dictionary
An instrument of war; a light spear. “Fiery darts” (Eph. 6:16)
are so called in allusion to the habit of discharging darts from
the bow while they are on fire or armed with some combustible
material. Arrows are compared to lightning (Deut. 32:23, 42; Ps. 7:13; 120:4).
International Standard Bible Encyclopedia
dart (chets; belos): A pointed missile weapon, as an arrow or light spear (2Sa 18:14; Job 41:26). See ARMOR; ARMS, III, 4; ARROW. Figurative:
(1) Of the penalty of sin (Pr 7:23 the King James Version);
(2) of strong suggestions and fierce temptations to evil (Eph 6:16; compare 1 Macc 5:51).