Welder n. : One who welds, or unites pieces of iron, etc., by welding.

Welder n. : One who welds, or wields.

Welder n. : A manager; an actual occupant.

Example:
What size Welder do I need to do a medium sized jobs such as welding a go kart together?

Taxonomy
Welder, exposure, free encyclopedia, flames, particles, arc welding, welding procedures, welds, helmet, processes, risks, electric arc, burns, face plates, UV light, curtains, ASM International, equipment used.

Defination from the web:
welder (also weldor, which term distinguishes the tradesman from the equipment used to make welds) is a tradesman who specialises in welding materials together. ... Welders typically have to have good dexterity and attention to detail, as well as some technical knowledge about the ...