Literally means "next to last". In street speak it takes on the meaning "second to none" or simply used to describe something utterly appeasing. It is easy to get away with using this word because of it's confusion with "ultimate" by those who don't know any better.

Marginalized Orientations, Gender identities, And Intersex. it’s meant to be an all inclusive umbrella term for asexuals, homosexuals, multisexuals, trans people, and intersex people. Alternative to LGBTQIAP+
Alternative to MOGII, easier to pronounce.

While usually meaning the second to last, it has also been used to mean the absolute best, or most ultimate.

(adj.) Last but one in a series of things, second to last