Vapogender is a xenogender which feels like smoke. One can see it and understand it on a shallow level but if one tries to go deeper it disappears, and one is left with no gender and only tiny wisps of the gender one thought it was. Vapogender can be combined with other gender terms (vapoboy, vapogirl, vapofluid, etc.)
Vapogender was coined on June 16, 2015 by an anonymous asker on pride-flags-for-us on tumblr.
The flags with the symbol were created on August 23, 2015 by tumblr user pastelmemer.