We know that duck is sometimes a tasty meal, however, how did the term "duck" referring to watchout, lower your head, etc. come about?

ArlingtonVA

It seems as simple as evolving from its more literal meaning, of to thrust one's head under water, to evade. duck Function: verb Etymology: Middle English douken; akin to Old High German tūhhan to dive, Old English dūce duck Date: 14th century transitive verb1: to thrust under water2: to lower (as the head) quickly : bow3: avoid, evade intransitive verb http://www.merriam-webster.com/dictionary/ducking Jul 07 09, 8:02 PM