lumch
When your colleagues think it's funny to purposefully misspell "lunch" to announce their leave for an afternoon food break within a chat client or SMS message. It originates from a genuine typo that escalated solely to aggravate those who appreciate good grammar. People who use "lumch" intentionally are commonly regarded as idiots.
I'm AFK to get some lumch.
Lumch
When your coworker leaves a Yelp review and doesn't spell check.
I love to take a good dump after I eat lumch!!