1. (v. i.) To unite, embrace, communicate with, or flow into, one another; to be connected in one system; to lock into one another; to interlace firmly.

2. (v. t.) To unite by locking or linking together; to secure in place by mutual fastening.

accord aegis agree answer to arm guard assent assort with backstop be consistent be of one be uniform with buffer bulwark bumper check chime cohere coincide concur conform conform with consist with contraceptive cooperate copyright correspond crash helmet cushion dashboard dodger dovetail face mask fall in together fender finger guard fit together foot guard fuse go together go with goggles governor guard guardrail hand guard handrail hang together hard hat harmonize helmet hit hold together insulation interaffiliate interally interassociate interconnect intercouple interdepend interdigitate interjoin interlink interrelate intersect intertie jibe knee guard knuckle guard laminated glass life preserver lifeline lightning conductor lightning rod lock mask match mudguard nose guard overlap pad padding palladium parallel patent pilot preventive prophylactic protective clothing protective umbrella register register with respond to safeguard safety safety glass safety plug safety rail safety shoes safety switch safety valve screen seat belt shield shin guard sing in chorus sort with square square with stand together sun helmet tally umbrella windscreen windshield