Is Shipfitter One Word or Two?

Shipfitter is a noun. A noun is a type of word the meaning of which determines reality.

How do you spell the word shiplap?

noun Carpentry. an overlapping joint, as a rabbet, between two boards joined edge to edge.

What is a shipfitter in the Navy?

1 : one that fits together the structural members of ships and puts them into position for riveting or welding. 2 : a naval enlisted man who works in sheet metal and performs the work of a plumber aboard ship.