Reactive or functioning or allowing movement in two usually opposite directions.
Operating in two directions. A bidirectional printer can print from left to right and from right to left; a bidirectional bus can transfer signals in both directions between two devices. bi-directional.

1. Having or formed by a change of direction; doubled on itself
2. Played, delivered, or given in return; taking place for the second time
3. Used or taken on returning
4. Returning or permitting return
5. Of, relating to, or causing a return to a place or condition