What is the meaning of Lowboy?

A low chest of drawers.

A semi-trailer designed for hauling vehicles and other mobile equipment, with two drops in deck height: one right after the gooseneck and one right before the wheels; so named because the trailer's main deck is situated close to the ground for easy loading and unloading of vehicles and equipment.

A precursor to the hi-hat drum, with a pair of cymbals low to the ground that are struck with a foot pedal.

Source: wiktionary.org