thorn
noun [ C ] uk/θɔːn/ us/θɔːrn/
（植物茎上的）刺，荆棘
a small, sharp pointed growth on the stem of a plant
Idiom
thorn in your flesh/sideidiom 肉中刺，眼中钉
a person or thing that repeatedly annoys you or causes you pain
A relentless campaigner, he was a thorn in the government's side for a number of years. 作为一名不屈不挠的活动家，多年来他一直是政府的眼中钉。