Duck \Duck\, v. t. [imp. & p. p. Ducked; p. pr. & vb. n. Ducking.]

[OE. duken, douken, to dive; akin to D. duiken, OHG. t?hhan, MHG. tucken, t["u]cken, t?chen, G. tuchen. Cf. 5th Duck.]

1. To thrust or plunge under water or other liquid and suddenly withdraw.

Adams, after ducking the squire twice or thrice, leaped out of the tub. --Fielding.

2. To plunge the head of under water, immediately withdrawing it; as, duck the boy.

3. To bow; to bob down; to move quickly with a downward motion. `` Will duck his head aside.'' --Swift.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Ducking \Duck"ing\, n. & a., from Duck, v. t. & i.

Ducking stool, a stool or chair in which common scolds were formerly tied, and plunged into water, as a punishment. See Cucking stool. The practice of ducking began in the latter part of the 15th century, and prevailed until the early part of the 18th, and occasionally as late as the 19th century. --Blackstone. Chambers.

Source: Webster's Revised Unabridged Dictionary (1913)