Sailor's Gravy is a mix between diarrhea and vomit. Comes from the fact hat when a person gets sea sick they puke and shit all at once.
The port-a-potty at the fair was full of sailor's gravy - those people were puking and shitting their guts out.
A homosexual who likes to give anal to somebody with severe diahorrea.
"That guy in the navy was a complete gravy sailor."