(1):

(v. i.) To differ in opinion; to hold discordant views; to be at controversy; to quarrel.

(2):

(v. i.) To fail to accord; not to agree; to lack harmony; to differ; to be unlike; to be at variance.

(3):

(v. i.) To be unsuited; to have unfitness; as, medicine sometimes disagrees with the patient; food often disagrees with the stomach or the taste.