1. An offill is someone who steals things by simply being absent minded or someone who does it on purpose and claims innocence.
2. An offill is a friend who will mooch off of you to the point of even thievery. Typically one who borrows things like tools, electronics, and money and never return them.
Oh I'm sorry Officer... I accidentally drove off without paying for my gasoline at the Texaco station up the road
Winona Ryder was caught in 2001 trying to leave Saks Fifth Avenue with more than $5,000 worth of merchandise, she claims she was under heavy meds, but typical signs of an offill.
Hey, it's your brother John Doe... What's up brother... Do you have a power sander I can borrow?... Well I used to however my friend Dwayne is such an Offill I never saw it again...