An oath or affirmation; a vow

“if I make a promise, I always stick to it;  he broke his promise”

A transaction between two persons whereby the first person undertakes in the future to render some service or gift to the second person or devotes something valuable now and here to his use

Reason to expect improvement or success; potential

“She shows great promise as an actress.”

To commit to (some action or outcome), or to assure (a person) of such commitment; to make an oath or vow.

“He promised to never return to this town again.”

To give grounds for expectation, especially of something good.

“The clouds promise rain.”