plant material vs chaff

plant material and chaff both are nouns.

Word	Noun	Adjective	Verb	Adverb
plant material	Yes	No	No	No
chaff	Yes	No	Yes	No

As nouns, chaff is a hyponym of plant material; that is, chaff is a word with a more specific, narrower meaning than plant material:

plant material: material derived from plants
chaff: material consisting of seed coverings and small pieces of stem or leaves that have been separated from the seeds

Other hyponyms of plant material include cutin, husk, shuck, stalk, straw, stubble, cork, plant product, vegetable tallow, wood.

plant material (noun)	chaff (noun)
material derived from plants	foil in thin strips; ejected into the air as a radar countermeasure
	material consisting of seed coverings and small pieces of stem or leaves that have been separated from the seeds

plant material (verb)	chaff (verb)
	be silly or tease one another