not consisting of matter; "immaterial apparitions"; "ghosts and other immaterial entities"
(often followed by `to') lacking importance; not mattering one way or the other; "whether you choose to do it or not is a matter that is quite immaterial (or indifferent)"; "what others think is altogether indifferent to him"
of no importance or relevance especially to a law case; "an objection that is immaterial after the fact"
make a counterattack and return like for like, especially evil for evil; "The Empire strikes back"; "The Giants struck back and won the opener"; "The Israeli army retaliated for the Hamas bombing"
any backward region that is isolated from the world and resists progress
a body of water that was created by a flood or tide or by being held or forced back by a dam; "the bayous and backwaters are breeding grounds for mosquitos"