set one's heart on

set (one's) heart on (something)

To be resolutely or inflexibly determined to do or acquire something. When I was a little boy, I set my heart on becoming a fighter pilot. When Janie sets her heart on a new toy, she won't give us a moment's peace until we buy it for her.
See also: heart, on, set

set one's heart on

Also, have one's heart set on. Strongly desire something, as in I'd set my heart on a vacation in New Mexico but got sick and couldn't go, or Harry had his heart set on a new pickup truck. [Late 1300s]
See also: heart, on, set