under one's thumb or under the thumb {adj.} or {adv. phr.}
Obedient to you; controlled by you; under your power.
The Jones family is under the thumb of the mother.
Jack is a bully. He keeps all the younger children under his thumb.
The mayor is so popular that he has the whole town under his thumb.
Compare: JUMP THROUGH THE HOOP. Categories: adjective adverb