A person who makes slots or grooves in something, especially as a job or a hobby.
Being a slotters means you are good at making slots or grooves, and it could be a job or something you do for fun.
Examples:
The slotters made a groove in the wood.
My dad is a slotters, he makes slots in metal.
The slotters is very good at making grooves.
The slotters is the best at making slots.
The slotters can make a groove in anything.
I want to be a slotters when I grow up.