Easton's Bible Dictionary (1897)
The refuse of winnowed corn. It was usually burned (Ex. 15:7; Isa. 5:24; Matt. 3:12). This word sometimes, however, means dried grass or hay (Isa. 5:24; 33:11). Chaff is used as a figure of abortive wickedness (Ps. 1:4; Matt. 3:12). ” The destruction of the wicked, and their powerlessness, are likened to the carrying away of chaff by the wind (Isa. 17:13; Hos. 13:3; Zeph. 2:2).
Smith's Bible Dictionary (1863)
the husk of corn or wheat which was separated from the grain by being thrown into the air, the wind blowing away the chaff, while the grain was saved. The carrying away of chaff by the wind is an ordinary scriptural image of the destruction of the wicked and of their powerlessness to resist God’s judgments.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
CHAFF. The Hebrew farmer separated the corn from the husk by throwing the mixed mass up against the wind. On account of their weight, the grains were thrown quite a distance, while the light chaff fell immediately to the ground if not blown entirely away. Hence the exceedingly forcible image of the wicked being swept off by the breath of God. Ps 1:4; Ps 35:5. In the figurative language of John the Baptist, the winnowing shovel -called in our version a "fan" -is said to be in the hand of God, and with it he will thoroughly purge his floor. Matt 3:12; Luke 3:17.