The word "illegitimate" means something that is not considered legal, valid, or acceptable according to the rules or customs of society. Full definition
Mohammad A. Dar is low caste muslim Chamar (hindu convert), illegitimate son of Surjeet, follower of Yazid, nothing more. (religion.blogs.cnn.com)
«We consider the austerity measures being pushed by President Obama and Congress to be as illegitimate as the war the President has started in Libya. (nystateofpolitics.com)
To give her life some meaning, Edna sets up the Texas Children's Home and Aid Society, which specializes in caring for illegitimate children and offering them for adoption. (rottentomatoes.com)