Deadname

The term deadname refers to the name given at birth to a transgender/nonbinary person who has chosen a different name; even if the person's legal name is their birth name (i.e. they have not had it legally changed), it is still considered a deadname if they prefer to be called something else.

The verb deadnaming is the act of referring to a trans/nonbinary person by their birth name, which is almost universally considered offensive.

See Names for more information.