Definition of stiff:
of an object, rigid
, hard to bend, inflexible
; of policies and rules and their application and enforcement, inflexible
"he was eventually caught, and given a stiff fine."
an average person, usually male, of no particular distinction, skill, or education, often a working stiff or lucky stiff; a person who is deceived, as a mark
in a swindle
"she convinced the stiff to go to her hotel room, where her henchman
was waiting to rob him."
"realizing he had forgotten his wallet, he stiffed the taxi driver when the cab stopped for a red light."