A person, typically homeless, who lives by asking for money or food from others. The beggar sat on the corner, holding a sign that asked for help.
A person reduced to extreme poverty or destitution. The war left him a beggar with nothing but the clothes he wore.
(informal, chiefly British) A playful or mildly reproachful form of address to a person, often implying admiration, surprise, or mild annoyance. You lucky beggar, winning the lottery on your first try!