bidirectional /bī-dī-rekˈshə-nəl/

1. Operating or passing signals in two directions
2. Printing the lines of a text alternately left to right and right to left (computing, etc)

• postal code
• postal codes
• postally
• postal meter
• postal meters
• postal note
• postal notes
• postal order
• postal orders
• postals
• postal tube
• postal tubes
• postal union
• postal unions
• postal vote
• postal votes
• post and pair
• postbag
• postbags
• post-bellum
• postbox
• postboxes
• post boy
• post boys
• postbus