not authorized by the law; not in accordance with accepted standards or rules

defending workers against illegitimate managerial practices

an illegitimate exercise of power by the military

the new powers are illegitimate

(of a child) born of parents not lawfully married to each other

Henry VIII's illegitimate son, Henry Fitzroy

he is an illegitimate descendant of a wealthy New York dynasty

a person born of parents not lawfully married to each other