kapok vs vegetable silk

kapok and vegetable silk both are nouns.

Word	Noun	Adjective	Verb	Adverb
kapok	Yes	No	No	No
vegetable silk	Yes	No	No	No

As nouns, kapok and vegetable silk are synonyms defined as:

kapok and vegetable silk: a plant fiber from the kapok tree; used for stuffing and insulation

Other synonyms of kapok include silk cotton.

kapok (noun)	vegetable silk (noun)
massive tropical tree with deep ridges on its massive trunk and bearing large pods of seeds covered with silky floss; source of the silky kapok fiber	a plant fiber from the kapok tree; used for stuffing and insulation
a plant fiber from the kapok tree; used for stuffing and insulation