( Frost ( ( is ( ( the formation ) ( of ( ( ( ( ice crystals ) ( on ( the ground ) ) ) or ) ( ( other surfaces ) ( in ( ( the form ) ( of ( scales ( , ( needles ( , ( ( feathers or ) fans ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Frost)) (VP (VBZ is) (NP (NP (DT the) (NN formation)) (PP (IN of) (NP (NP (NP (NN ice) (NNS crystals)) (PP (IN on) (NP (DT the) (NN ground)))) (CC or) (NP (NP (JJ other) (NNS surfaces)) (PP (IN in) (NP (NP (DT the) (NN form)) (PP (IN of) (NP (NNS scales) (, ,) (NNS needles) (, ,) (NNS feathers) (CC or) (NNS fans)))))))))) (. .)))
Frost is the formation of ice crystals on the ground or other surfaces in the form of scales, needles, feathers or fans.
(ROOT (S (NP (NP (DT The) (NN ice) (NNS crystals)) (SBAR (WHNP (WDT that)) (S (VP (VBP form) (PP (IN on) (NP (DT the) (NN ground))))))) (VP (VBP are) (VP (VBN called) (S (ADJP (JJ frost))))) (. .)))