[1] : WordNet (r) 2.0

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

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

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

[3] : Bouvier's Law Dictionary, Revised 6th Ed (1856)

pater. father. a term used in making genealogical tables. 

Pater >> P Words
Pater, definition of term: Pater
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