In general, a declaration, written or verbal, made by one person to another, which binds the person who makes it to do, or to forbear to do, a specified act; a declaration which gives to the person to whom it is made a right to expect or to claim the performance or forbearance of a specified act.(adjective)
source: webster1913
noun (n)
a verbal commitment by one person to another agreeing to do (or not to do) something in the future(noun.communication)
source: wordnet30
grounds for feeling hopeful about the future(noun.cognition)
Example: There is little or no promise that he will recover.
To engage to do, give, make, or to refrain from doing, giving, or making, or the like; to covenant; to engage; as, to promise a visit; to promise a cessation of hostilities; to promise the payment of money.(verb)
source: webster1913
To give assurance by a promise, or binding declaration.(verb)