( ( BRASS ( ( An alloy ) ( of ( ( copper and ) zinc ) ) ) ) . )
(ROOT (NP (NP (NNS BRASS)) (NP (NP (DT An) (NN alloy)) (PP (IN of) (NP (NN copper) (CC and) (NN zinc)))) (. .)))
BRASS An alloy of copper and zinc.
(ROOT (S (NP (NNP Brass) (NNP alloy)) (VP (VBZ is) (VP (VBN made) (PP (IN from) (NP (NN copper) (CC and) (NN zinc))))) (. .)))