Etymology-2.

संस्कृत > saṃskṛta > √ग्रस् > √gras > to gobble, to chew / to cud > 
grass (noun) > to graze (verb),√चर् > √car > √चर्व > √carv > चरना > caranā >  पशुचर > paśucara > pasture / pastor, चबाना > cabānā > chaff, to chaff (cut the grass) √गॄ > निगरणे > gṛ > nigaraṇe 
> गृणं / गृणनं > gṛṇaṃ / gṛṇanaṃ > green .>  हृ > हरित > > hṛ > harita > hārita  > horti-(culture)
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