1. The moment when your slobber gets sucked in your throat and you swallow it and choke on it at the same time.
2. Also when a girl chokes on a cum while giving a blowjob.
2b. Thwoller can replace swaller when referring to a gay guy swallering on cum while giving a blowob.
"My girl was telling me one morning she woke up because she had swallered."
"She don't spit or swallow, she swaller!"
"He totally thwoller on me all the time!"
A man or woman who can ingest a lot of items of varying sizes of loads, thickness, viscosity, volume etc. etc. with relative easy and alacrity.
This chick on 3rd Avenue is a real good swaller man.
Amazing to watch her work.