Student or Learner
'a four-letter man'
Does it mean 'a disgusting man'?
Do you also say 'a four-letter woman' or
'a four-letter person'?
I think it is a disgusting person that is meant here, yes. I'd also suggest that you can call "a four-letter man" a guy swearing like a sailor
I'm not sure if I'm right though. Let's wait what native speakers will say