Polygender, also called poly-gender or multigender, is an umbrella term, but may also be used as a specific gender identity. Someone who is polygender has more than one gender. They may have two (bigender), three (trigender), or more, or even virtually all genders (pangender). Polygender can mean that a person has all these genders at the same time, in a mix. Polygender can also mean that they change from one gender to the next at different times, in which case the word is used interchangeably with genderfluid. Polygender identities all fall under the nonbinary and transgender umbrellas. A polygender person could have been assigned any gender at birth, and they may or may not seek a physical transition to change their body. In cassolotl's Nonbinary Stats Survey 2016, only 7 respondents used the word "polygender" for themselves. However, some specific polygender identity labels were more commonly used: there were 137 self-described "bigender" respondents in Nonbinary Stats Survey 2013, and 123 in Nonbinary Stats Survey 2016. For self-described "genderfluid" respondents, the Nonbinary Survey found 645 in 2013, and 942 in 2016.