Somebody's alternate personality or persona; another self.
A very close and intimate friend.
A corporation used by a person to conduct personal business in an attempt to shield himself or herself from personal liability, and which a court may penetrate by "piercing the corporate veil" to impose liability on the person when they commit fraud or injustice.
brother (a male comrade or friend; one who shares one’s ideals)
fratboy (or someone that espouses the fraternity bro culture)
brother (usually used to address a male)
brother (a male sibling)
he or him