Webster's Revised Unabridged Dictionary · 1913

Decoy

Decoy (de*koi") , transitive verb

[Prefix de- + coy; orig., to quiet, soothe, caress, entice. See Coy.]

To lead into danger by artifice; to lure into a net or snare; to entrap; to insnare; to allure; to entice; as, to decoy troops into an ambush; to decoy ducks into a net.
Did to a lonely cot his steps decoy. — Thomson
E'en while fashion's brightest arts decoy, The heart, distrusting, asks if this be joy. — Goldsmith

Decoy , noun

1.
Anything intended to lead into a snare; a lure that deceives and misleads into danger, or into the power of an enemy; a bait.
2.
A fowl, or the likeness of one, used by sportsmen to entice other fowl into a net or within shot.
3.
A place into which wild fowl, esp. ducks, are enticed in order to take or shoot them.
4.
A person employed by officers of justice, or parties exposed to injury, to induce a suspected person to commit an offense under circumstances that will lead to his detection.