Definitions for "Pawn chain"
Two or more like-colored pawns linked diagonally. The weakest point of a pawn chain is the base because that is the one pawn in the chain that cannot be defended by another pawn.
Two or more pawns of the same color linked together diagonally. (Diagram)
a set of pawns linked so each one is protected by a pawn behind it
connected pawns which protect each other e.g. c3-d4-e5. See the Pawn formations handout.