Hippie-half-share

Frugality taken to the next step, or all the way to your buddies fridge. Taking an almost unnoticeable amount of something (typically food) with the intention of replacing it... in some karmic form... at some distant future date, until there's only an unusable amount left.

Sage was a very courteous roommate, he was always thoughtful enough to leave a hippie-half-share of my milk in the fridge.