Alternative form of set one's heart on

(idiomatic) To be busy or thoroughly preoccupied.

To experience a certain “fluttery” physical sensation in a person's stomach, associated with nervousness, uncertainty, anxiety, or apprehension.

(idiomatic, Britain) To reprimand severely.

(idiomatic, intransitive) To be crazy or eccentric.

(idiomatic) To be organized; to have one's affairs in order; specifically, to have a multi-person effort coordinated towards the exact same goal.

(Australia) A jocular explanation for bad luck.

(US, humorous) Used to report that a (major) problem has occurred.

(idiomatic) To have someone in a difficult situation in which he or she is without alternatives and can be controlled.

(idiomatic) To have more important things to do.