incel

Short definition from Wiktionary

Noun

1. 1
   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.
2. 2
   An individual who is not sexually active despite having such a desire.
3. 3
   A misogynistic man, with the implication that his misogyny makes him undesirable to potential partners, thus limiting his romantic and/or sexual prospects.
4. 4
   "Involuntary celibacy": the state of being not sexually active despite wishing to be.

Adjective

1. 1
   Not having sexual relations despite wishing to.