For what it's worth, my reflex before reading a bunch of stuff here was closer to hearing "socially awkward man who can't manage to attract women" was closer to thinking of various annoying men who have hung around me, who I find unattractive (sometimes at the skin-crawling level [1]), but who never cross a line to the point where I feel justified in telling them to go away. This can go on for years. It is no fun.

After reading these discussions, I conclude that my preconception was a case of availability bias (possibly amplified by a desire to not know how painful things are), and so I use a more abstract category.

[1] To repeat something from a previous discussion, this isn't about being physically afraid. If I were, I'd be handling things differently. It also turned out to my surprise, that at least some men have never had the experience of that sort of revulsion. It seems to me that it's not quite the same as not wanting to be around someone who just about everyone would think was overtly ugly, though women frequently agree (independently, I think) about some men being uncomfortable to be around.

It wouldn't surprise me if there are specific elements of body language or facial expression which cause that sort of revulsion, but I don't know what they are.