timber vs shrillness

timber and shrillness both are nouns.

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

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

timber: (music) the distinctive property of a complex sound (a voice or noise or musical sound)
shrillness: having the timbre of a loud high-pitched sound

timber (noun)	shrillness (noun)
a beam made of wood	having the timbre of a loud high-pitched sound
a post made of wood	the quality of being sharp or harsh to the senses
(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