- noun device that extends an 8-bit bus to accommodate 16-bit add-in cards
- noun special board (used by repair engineers) that moves an add-in board up to a position that is easier to work on
- A device which expands the capabilities of a bus (1). It may be, for instance, an expansion board which provides multiple expansion slots.
- A board which physically distances a board in a computer from those surrounding it, to facilitate repairs and testing.