shack 1
/shak/ , n.
1. a rough cabin; shanty.
2. Informal. See radio shack .
v.i.
3. shack up , Slang.
a. to live together as husband and wife without being legally married.
b. to have illicit sexual relations.
c. to live in a shack: He's shacked up in the mountains.
[ 1875-80, Amer.; cf. earlier shackly rickety, prob. akin to RAMSHACKLE (MexSp jacal "hut" is a phonetically impossible source) ]
shack 2
/shak/ , v.t. Informal.
to chase and throw back; to retrieve: to shack a ground ball.
[ 1825-35, Amer.; appar. special use of dial. shack to SHAKE ]