( Weight ( ( is ( ( the force ) ( ( with ( which gravity ) ) ( pulls ( on ( a mass ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT the) (NN force)) (SBAR (WHPP (IN with) (WHNP (WDT which) (NN gravity))) (S (VP (VBZ pulls) (PP (IN on) (NP (DT a) (NN mass)))))))) (. .)))
Weight is the force with which gravity pulls on a mass.
(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)))))))))))) (. .)))