(1):

(a.) Not due; not yet owing; as, an undue debt, note, or bond.

(2):

(a.) Not right; not lawful or legal; improper; as, an undue proceeding.

(3):

(a.) Not agreeable to a rule or standard, or to duty; disproportioned; excessive; immoderate; inordinate; as, an undue attachment to forms; an undue rigor in the execution of law.