timber vs sylva

timber and sylva both are nouns.

Word	Noun	Adjective	Verb	Adverb
timber	Yes	No	No	No
sylva	Yes	No	No	No

As nouns, sylva is a hyponym of timber; that is, sylva is a word with a more specific, narrower meaning than timber:

Other hyponyms of timber include greenwood, riparian forest, silva, tree farm.

timber (noun)	sylva (noun)
a beam made of wood	the forest trees growing in a country or region
a post made of wood
(music) the distinctive property of a complex sound (a voice or noise or musical sound)
land that is covered with trees and shrubs
the wood of trees cut and prepared for use as building material