interlock
in.ter.lock \.int-*r-'la:k\ \'int-*r-.la:k\ \.int-*r-'la:k-*r\ vi : to become engaged or interrelated with one another 1: to lock together : UNITE 2: to connect so that motion of any part is constrained by another; esp : to arrange the connections of (as railroad signals) to ensure movement in proper sequence - in.ter.lock n