Multigender is a term for anyone who experiences more than one gender identity. It can be used as a gender identity in its own right, or can be an umbrella term for other identities which fit this description.
Multigender identities include bigender (two genders), trigender (three genders), quadgender (four genders), quintgender (five genders), polygender (many genders), pangender (all genders) and genderfluid (variable gender).
Multigender people may experience two or more gender identities at the same time, or their gender identity may change over time (genderfluid). The gender identities they experience may be male, female, non-binary, or genderless.
If a person experiences multiple genders and also experiences the fluctuation of those genders, they could possibly be multiflux and/or one of the varients of it. Multiflux is a term similar to multigender, but it relates to all genders encompassing multiple genders that also fluctuate in intensity.