on one's heels
01
closely following or pursuing someone or something, often in a persistent or bothersome manner
![on {one's} [heels] definition and meaning](https://cdn.langeek.co/photo/42800/original/?type=jpeg "on {one's} [heels] definition and meaning")
Idiom
Informal
例
He is constantly on my heels, checking my every move and questioning my decisions.
02
near the point of surpassing a fellow competitor
![on {one's} [heels] definition and meaning](https://cdn.langeek.co/photo/66324/original/?type=jpeg "on {one's} [heels] definition and meaning")
IdiomInformal例
If she does poorly on this exam, she may lose the title of valedictorian to one of the students on her heels.
