(1):

(v. t.) To make restoration or payment of an equivalent to (a person); to pay back to; to indemnify; - often reflexive; as, to reimburse one's self by successful speculation.

(2):

(v. t.) To replace in a treasury or purse, as an equivalent for what has been taken, lost, or expended; to refund; to pay back; to restore; as, to reimburse the expenses of a war.