dart, plant, X put off, sword, weapon

Boyd’s Bible Dictionary:

[ARMS
[WAR.]

Concise Bible Dictionary:

Arrow, short spear, javelin (2 Sam. 18:14; 2 Chron. 32:5; Job 41:26, 29; Prov. 7:23). FIERY DARTS signify darts tipped with combustible material which ignite in the projection or percussion and burn as well as pierce (Eph. 6:16: Compare Psa. 120:4). The Christian needs the shield of faith to quench such darts of the wicked one.

Strong’s Dictionary of Hebrew Words:

Transliteration:
shelach
Phonic:
sheh’-lakh
Meaning:
from 7971; a missile of attack, i.e. spear; also (figuratively) a shoot of growth; i.e. branch
KJV Usage:
dart, plant, X put off, sword, weapon

From Manners and Customs of the Bible:

Ephesians 6:16. The shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked.
Some have thought that the allusion here is to poisoned arrows. See note on Job 6:4 (#405). There were darts, however, sometimes used in ancient warfare that were literally “fiery.” They were hollow reeds filled with naphtha or some other combustible material, and, being set on fire, were shot from slack bows. Whatever the arrows struck, the flames consumed. Water served to increase their violence; they could only be extinguished by being covered with earth. Large shields were used by the soldiers against whom these “fiery darts” were thrown, and thus their persons were protected