Semen, specifically that of which is the result of fellatio. The use of the word is most effective around the holidays and in fall and winter. Neck Gravy is a bit too heavy and rich for hot weather.
"She gave me a blowjob and got a bigger helping of Neck Gravy than she expected."

"There's nothing wrong with that throat that a good dose of Neck Gravy won't cure."

"Pass the neck gravy, please."
by Poop S. December 21, 2005
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That creamy man gravy that she loves. Gobble gobble.
My girl is hungry for some neck bone gravy tonight. I shall feed her well.
by Eaton Holgoode March 6, 2017
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