a thorn in someone’s side
1
a person or thing that causes a lot of problems for someoneShe aims to be a thorn in the side of large global corporations.
Synonyms and related words
People and things that cause worry or problems
a bone of contention
a hostage to fortune
a nail in the coffin
Synonyms and related words
People who cause trouble or problems
troublemaker
nuisance
trial
See also main entry: thornSee also main entry: thorn