1. Similar to the meaning of polish or ploish, which means 'person who lives in poland', 'strange character's nickname in a brit gangster flick' or 'cunt'. This was originally a misspelling, but when time, blunt ignornace and stubborness are mixed they are unstoppable.
2. An excessor for the word cunt
"Well I'm sorry Luke (McGowan), but you just can't plosih a turd. Or indeed ploish a turd. Or polish one."