The facial expression achieved when you're taking a gigantic size bite out of a hamburger/hotdog and you expect ketchup but itstead it's fucking loaded with mustard.
"You should have seen that kid's mustard face after I falcon punched him in the testicles. Priceless."
"That old woman had a perfect mustard face after I crop dusted that elevator."
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).
Precedes or follows either a gratuitously disrespectful or honest remark, originated in New York City. Used in similar fashion to "no offense" or "to be honest," interchangeably.
Ya mans is wild buns, respectfully. Respectfully he's washed.
After school, The Modells on Jamaica Ave was active. Respectfully.