( ( ( ( The weight ) ( of ( an object ) ) ) ( is ( ( ( ( determined ( by ( ( the force ) ( of ( ( the pull ) ( of gravity ) ) ) ) ) ) ( on ( the ( object ( . ( Technically speaking ) ) ) ) ) ) , ) ( since ( gravity ( is ( a force ) ) ) ) ) ) ) ( , ( weight ( ( is ( a force ) ) . ) ) ) )
(ROOT (S (S (NP (NP (DT The) (NN weight)) (PP (IN of) (NP (DT an) (NN object)))) (VP (VBZ is) (VP (VBN determined) (PP (IN by) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NP (DT the) (NN pull)) (PP (IN of) (NP (NN gravity))))))) (PP (IN on) (NP (DT the) (NNP object) (. .) (NN Technically) (NN speaking))) (, ,) (SBAR (IN since) (S (NP (NN gravity)) (VP (VBZ is) (NP (DT a) (NN force)))))))) (, ,) (NP (NN weight)) (VP (VBZ is) (NP (DT a) (NN force))) (. .)))
The weight of an object is determined by the force of the pull of gravity on the object.  Technically speaking, since gravity is a force, weight is a force.
(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)))))))))))) (. .)))