"Bed rails" refers to a safety accessory that is attached to the sides of a bed to prevent someone from falling off while sleeping or resting. Full definition
The full - sized bed rails do not come with the crib. (creditdonkey.com)
The bed can be turned into a couch by placing the panels used as bed rails on one side. (omgstroller.com)
While it's designed specifically for use as a travel bed rail, you can make the most out of it during your regular co sleeping as well. (abckidsinc.com)