An ineffective person; a weakling.
A disabled, ineffectual, or helpless person or thing.
An elected official whose successor has already been elected, and who is serving out the remainder of a term.
(finance, slang, dated) A person who can not fulfil his contracts.
See lame duck.
Origin of lame-duck
18th century - A person who had defaulted in the London Stock Exchange was said to waddle out of Exchange Alley like a lame duck.