Batten

Batten is an implement used to hold something in place or as a fastening against a wall. It is typically a long flat strip of squared wood, metal, or plastic. It is used to secure the edges of a tarpaulin covering a ship's hatch, or to stiffen and extend the leech of a sail, especially when rough weather is expected. Thus battening came to mean to strengthen or fasten something with battens. Battening also came to mean thriving or prospering at the expense of someone else, such as a multinational company battening on the working classes.