monkey on back

a monkey on someone's back (American & Australian)

a serious problem that will not go away. The divorce proceedings are a monkey on her back.

See also: back, monkey

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a monkey on your back

a serious problem that you cannot forget. When you know you have to do everything perfectly, it puts a giant monkey on your back.

Usage notes: also used in the form get the monkey off your back to end a problem: By winning the championship, this team has finally got the monkey off its back.

Etymology: based on an earlier meaning of a monkey on your back (= a habit of using an illegal drug)

See also: back, monkey