Dictionary

A member of an online subculture of people (mostly men) who define themselves as unable to find a romantic or sexual partner despite desiring one.

Example: 2018 Alex Hern, Who are the 'incels' and how do they relate to Toronto van attack? The Guardian

Anyone who is not sexually active despite desiring to be.

(pickup community) "Involuntary celibacy": the state of not being sexually active despite wishing to be.

(pickup community) Not having sexual relations despite wishing to.