Definify.com
Webster 1913 Edition
Dad
Dad
(dăd)
, Noun.
[Prob. of Celtic origin; cf. Ir.
daid
, Gael. daidein
, W. tad
, OL. tata
, Gr. τάτα
, τέττα
, Skr. tāta
.] Father; – a word sometimes used by children.
I was never so bethumped with words,
Since I first called my brother’s father
Since I first called my brother’s father
dad
. Shakespeare