chair warmer

noun, Informal.
1.
an officeholder, employee, or the like, who accomplishes little, especially a person who holds an interim position.
2.
a person who lounges for long periods sitting in a chair, as in a hotel lobby or clubroom.
Origin
1905-10
Slang definitions & phrases for chair-warmer

chair-warmer

noun

An untalented and dispensable person; warm body (1909+)