carder / carter / karter [ˈkɑrdɜr]
carder – n. – 1. one who, or that which cards wool flax, etc.; 2. the brown-banded carder bee (Bombus humilis), a bumblebee found in most of Europe west of Russia
carter – n. – somebody who uses a cart for transporting goods or for farm work
karter – n. – one who drives a kart (see racing regulations)