chair warmer
noun Informal.
an officeholder, employee, or the like, who accomplishes little, especially a person who holds an interim position.
a person who lounges for long periods sitting in a chair, as in a hotel lobby or clubroom.
Origin of chair warmer
First recorded in 1905–10
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019