Crime against nature is a legal term use in published cases in the United States since 1814 and normally defined as a form of sexual behavior that is not considered natural and is seen as a punishable offense in several US states. In the broadest sense, a crime against nature could even include masturbation and unusual sexual positions, but these are not seen as such. Sexual practices that are often considered to be crimes against nature are anal sex, bestiality, homosexual acts, fellatio, cunnilingus and necrophilia. The term is sometimes also seen as a synonym for sodomy or buggery.