[1] : The Collaborative International Dictionary of English v.0.48

daddy \dad"dy\, n.
   diminutive of dad. --dryden.
   1913 webster
see also:
dad 

[2] : WordNet (r) 2.0

daddy
     n : an informal term for a father; probably derived from baby
         talk syn: dad, dada, pa, papa, pappa, pater,
          pop
see also:
dad dada pa papa pappa pater 
pop 

[3] : Moby Thesaurus II by Grady Ward, 1.0

19 moby thesaurus words for "daddy":
   abba, dad, father, foster father, genitor, governor, old man, pa,
   pap, papa, pappy, pater, paterfamilias, patriarch, pop, pops, sire,
   stepfather, the old man

Daddy >> D Words
Daddy, definition of term: Daddy
daddy_pag1.html

Daddy Longlegs >> D Words
Daddy Longlegs, definition of term: Daddy Longlegs
daddy+longlegs_pag1.html

Sugar Daddy >> S Words
Sugar Daddy, definition of term: Sugar Daddy
sugar+daddy_pag1.html