lingual artery: an artery originating from the external carotid artery and supplying the under side of the tongue
artery: a blood vessel that carries blood from the heart to the body
dead metaphor: a metaphor that has occurred so often that it has become a new meaning of the expression (e.g., `he is a snake' may once have been a metaphor but after years of use it has died and become a new sense of the word `snake')