The term 'Bundler, Hay' is a job description that involves the use of a BALER to compress hay into bales. The BALER is a machine that compresses hay into a tight bundle, and the bales are then tied together with twine or wire. The baled hay can then be stored or transported for use in various applications. The bundler is responsible for operating the BALER, ensuring that the hay is properly compressed and tied, and then stacking the bales for transport or storage.