That's not an incel. It's slang so there's only an urban dictionary definition, but still, this is pretty spot on:

"a person (usually male) who has a horrible personality and treats women like sexual objects and thinks his lack of a sex life comes from being "ugly" when its really just his blatant sexism and terrible attitude. incels have little to no self awareness; even when they see other "ugly" men with girlfriends, they consider these men to be tricksters who have somehow beat the system and can get women despite being cursed with unattractiveness (in other words, theyre respectful to women and women are attracted to their personalities, but incels cant comprehend such a phenomenon). they believe that women owe them sex, and many of the more extreme incels like to spend time in incel communities on the internet coming up with ways to make women have sex with them (often involving genocide of people of color, genocide of "Chads" (men who have sex), taking rights away from women, raping them, having sex with women's dead bodies, and other horrid, disgusting things. they cant understand that that is PRECISELY why women want nothing to do with them)."