a/the monkey on somebody's back

a monkey on (one's) back

1. slang A drug addiction. Did you hear? Pete checked himself into rehab to deal with the monkey on his back.
2. A burden. This project is such a monkey on my back right now—I can't wait for it to be over.
See also: back, monkey, on

a/the ˌmonkey on somebody’s ˈback

1 a difficult problem that somebody cannot solve or get rid of: The accusations of fraud remain a monkey on her back.
2 (slang) the state of being unable to stop using drugs
See also: back, monkey, on