escargot, n. — Green’s Dictionary of Slang

escargot n.

[Fr. escargot, a snail; such couples appear curled up as tightly as a snail in its shell; Eble, Slang & Sociability (1996), prefers play on his cargo, i.e. the woman is the man’s cargo]

(US campus) a man walking arm in arm with his date.

1984		Eble Campus Sl. Mar.
1996		Eble Sl. and Sociability 78: At least two French expressions have preserved form but with meanings entirely different from their sources. [...] Escargot, ‘snail’ in French, in a play on his cargo or his car go in English means ‘male walking arm in arm with his date’.