( ( ( The weight ) ( of ( an object ) ) ) ( ( is ( ( the force ) ( of ( gravity ( on ( that object ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN weight)) (PP (IN of) (NP (DT an) (NN object)))) (VP (VBZ is) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NP (NN gravity)) (PP (IN on) (NP (DT that) (NN object))))))) (. .)))
The weight of an object is the force of gravity on that object.
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (DT the) (NN measure)) (PP (IN of) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NP (NN gravity)) (VP (VBG pulling) (PRT (RP down)) (PP (IN on) (NP (DT an) (NN object)))))))))))) (. .)))