Origin: Latin prefix sub-
Subcontractor has 2 different meanings across 1 category:
someone who enters into a subcontract with the primary contractor
"The general contractor hired a specialized electrical firm as a subcontractor to handle the wiring for the new hospital wing."
A contractor hired by a general contractor employed by the contractor rather than directly hired by the customer.
"The general contractor had to hire an electrical subcontractor since they did not have their own licensed electricians on staff."