duck2

verb

• 1 [no object] lower the head or the body quickly to avoid a blow or missile or so as not to be seen:spectators ducked for cover [with object]:he ducked his head and entered
• [with object] avoid (a blow or missile) by moving quickly:he ducked a punch from an angry first baseman
• [with object] informal evade or avoid (an unwelcome duty or undertaking):a responsibility which a less courageous man might well have ducked [no object]:I was engaged twice and ducked out both times

• 2 [with object] push or plunge (someone) under water, either playfully or as a punishment:Rufus grabbed him from behind to duck him under the surface

• 3 [no object] Bridge refrain from playing a winning card on a particular trick for tactical reasons: declarer ducked the opening spade lead

noun

• a quick lowering of the head.