Term originated by bike mechanics, for the force of nature that causes small objects dropped in the vicinity of a refridgerator to be drawn underneath it, out of reach of human hands. Valuable items and irreplaceable mechanical parts are particularly prone to fridge suck.
Person #1: Can you hold on this vitally important bush while I grease up the flange? Don't drop it, it'll get caught in the fridge suck.
Person #2: Sure, I- Oh. Bugger. Did you see where it went?