'Probably' definitions:

Definition of 'probably'

From: WordNet
adverb
With considerable certainty; without much doubt; "He is probably out of the country"; "in all likelihood we are headed for war" [syn: probably, likely, in all likelihood, in all probability, belike]
adverb
Easy to believe on the basis of available evidence; "he talked plausibly before the committee"; "he will probably win the election" [syn: credibly, believably, plausibly, probably] [ant: implausibly, improbably, incredibly, unbelievably]

Definition of 'Probably'

From: GCIDE
  • Probably \Prob"a*bly\, adv. In a probable manner; in likelihood. [1913 Webster]
  • Distinguish between what may possibly and what will probably be done. --L'Estrange. [1913 Webster]

Synonyms of 'probably'

From: Moby Thesaurus