Agender is a term that applies to people who do not identitify as any gender or who identify as having a lack of any specific gender. Some use a gender identity that is neutral.
More About Agender
There are several identities that fall under the umbrella of agender. These identities are similar in that they are genderless. However, they are all distinct. These include anongender, apogender, agenderfluid, agenderflux, cancegender, genderblank, gendernull, gendervoid, librafluid, null gender, and oneirogender.