(1):

(v. t.) To meet or fall in with, as something inconvenient, harmful, or onerous; to put one's self in the way of; to expose one's self to; to become liable or subject to; to bring down upon one's self; to encounter; to contract; as, to incur debt, danger, displeasure/ penalty, responsibility, etc.

(2):

(v. t.) To render liable or subject to; to occasion.

(3):

(v. i.) To pass; to enter.