Definition of big man:
(n) :
(figurative) An alpha male.
(n) :
(anthropology) A male individual in a tribe who has great status and influence, especially in Melanesia and Polynesia.
(n) :
(politics) A corrupt, autocratic ruler.
(n) :
(American football, informal) A lineman.
(n) :
(endearing) Synonym of big guy (“term of endearment”).