Amplusian

Amplusian or Amplusgender refers to a gender that is not strict or constant. One's gender might be fluid, fluctuating, or both, or they could be in a grey-area between genders. It is miscellaneous, varied, and changing. Amplusian can be used as an umbrella term for any gender that changes in any way.

It is the opposite of suptilian.

History
Amplusian was coined by the Tumblr blog arco-pluris on March 15, 2018. On February 20, 2020, the Tumblr blog Gender Resource (which compiles various gender terms) elaborated on the etymology of the term, stating that the root "amplus" came from Latin, "an adjective meaning 'abundant' or 'ample'."