Green’s Dictionary of Slang

1. to leave, to go, to accompany.

1888		‘Rolf Boldrewood’ Robbery under Arms (1890) 99: The rest of us...as they was sold, stashed the camp and cleared out different ways.
1960		I. Freeman Out of the Burning (1961) 134: I picked out a few good guys [...] to stash with me right into Gus’s turf. [Ibid.] 143: I stashed over to the girls.
1969		B. Beckham My Main Mother 176: The morning I was to stash out for Rhode Island was too chilly.

2. (US) to walk in, to enter; to visit, to arrive at.

1975		E. Torres Carlito’s Way 58: I used to like to stash into the joint with a big party.
1977		E. Torres Q&A 94: We stash in cool.