1. (adj) ripped, buff, huge, or muscular
"Yo, check these guns; I fucking got jacked working in the quarry this summer."
2. (past tense) stolen
"Never park on MLK Blvd, unless you want your car to get jacked."
3. (past tense) hit, pounded, blasted, housed, or punched
"Don't fucking say that shit about MLK, unless you want to get jacked in the face -- bitch."