dad

Etymology 1

From Early Modern English dadd, dadde (circa 1500), undoubtedly older, from unrecorded Middle English *dadde, of uncertain ultimate origin. * Perhaps of Celtic origin, compare Welsh and Breton tad (from Proto-Brythonic *tad), Old Irish data; and possibly related to Russian дя́дя (djádja, “uncle”) and/or Russian де́душка (déduška, “grandfather”), all imitative. In Welsh, after triggering a soft mutation, 'Tâd' turns into 'Dâd'. * Perhaps imitative of a child's first uttered syllables da, da. * Possibly from a metathetic variation of unrecorded Old English *ætta, *atta (“father”), from Proto-West Germanic *attō, from Proto-Germanic *attô ("father, forefather"; whence also North Frisian ate, aatj, taatje, tääte (“father; dad”), German Tate (“dad”), Bavarian tatte (“dad”), Cimbrian tatta (“dad”), Icelandic táta (“dad”)), from Proto-Indo-European *átta (“father”), whence Sanskrit तत (tata, “father”).

noun

1. (informal) A father, a male parent.
   His dad was always there for him.
2. Used to address one's father
   Happy Father's Day, Dad!
3. (slang) Used to address an older adult male

Etymology 2

From dade (“to strike heavily”), dade (“a heavy blow or thud”). Probably onomatopoeic.

noun

1. A lump or piece.
2. A blow; act of striking something.

verb

1. (transitive) To throw against something; to dash.