A person who steals or reinnacts another persons (usually someone popular) jokes, words or other personal mannors. Essentially trying to become another person. This can sometimes occur unconsciously.
Boy tryin to jack my swagger to get dem ladies. A swagger jacker, swacker. Good thing u cant beat the original!
American: Hey bro, want some chips?
British: So you call these things "chips" instead of crispity crunchy munchie crackerjack snacker nibbler snap crack n pop westpoolchestershireshire queen's jovely jubily delights? Thats rather bit cringe, innit bruv