We don't have synonyms for bigass yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are big-ass, bigas and big ass.
(adj) :
Alternative form of big-ass. [(vulgar, slang) Very large; especially, very large and also expansive, fat, impressive, muscular, intimidating, or important.]
(adj) :
Alternative form of big-ass. [(vulgar, slang) Very large; especially, very large and also expansive, fat, impressive, muscular, intimidating, or important.]