Letters that make add-in
a, d, n, i are letters that make 'add-in'
1 possible definitions for 'add-in'
Under this definition, add-in is a noun and has the following properties:
circuit board, circuit card, plug-in, card, board have the same meaning as 'add-in'
'add-in' can be a type of printed circuit.
CPU board, mother board, PC board are types of 'add-in'.