have a tight grip on (someone or something)

have a tight grip on (someone or something)

To maintain strict or tight control over someone or something; to not allow someone or something very much independence or autonomy. Ever since George lost most of their life savings in a drunken poker match, Dana has had a tight grip on the family finances. The boss has had a tight grip on her assistant ever since she first hired him.See also: grip, have, on, tight