Tumblrgender is a xenogender related to Tumblr. One who is tumblrgender feels as if their gender is closely connected to the social media site Tumblr. It can also be used as a reclaimed term, coined for those who are frequently assumed to be faking being transgender for attention. This definition is closely related to gender non-conforming trans individuals, xenic individuals, those who use neopronouns, etc.
History
The term first appeared around a similar term, trendergender, meaning that someone was 'pretending' to be transgender, usually due to having a xenogender, using neopronouns, being gender non-conforming, etc. It came from a lot of these concepts being extremely popular on Tumblr.
On April 10th, 2021, Tumblr user incusins made a post coining two new definitions for tumblrgender, including two new flags they made for the term.[1]
Flag
The flags were created by the same user on the same date. They have no confirmed meanings.