Stuff
Stuff turns up in 2 fields: PCBs, maritime. Here is what it means to the people in each one.
Stuff in PCBs
To load components onto a bare board, by hand or machine; a stuffed board is an assembled one.
Stuffing a board means populating it with components, and a stuffed board is an assembled one as opposed to a bare board. The word comes from hand-inserting through-hole parts but is used for any assembly method. Engineers often ask for partly stuffed boards when they want to bring up a design one section at a time, leaving the rest unpopulated.
"Have them stuff only the power supply section on two of the boards, we'll bring those up first."
Stuff in maritime
A traditional mixture of tallow, pine tar, or resin used to protect rigging.
A generic shipyard and rigging term for various protective mixtures smeared over masts, standing rigging, and hull seams. Slushing stuff is typically made of animal fat and protects exposed wood and metal from saltwater corrosion. Paying stuff is a hot pitch or resin mixture poured into deck seams to make them watertight.
"Grab a bucket of slushing stuff and get to work on the mainmast before the weather turns."