Dictionary.com
definitions

vegetable silk

noun
  1. a fine, glossy fiber, similar to silk cotton, from the seeds of a spiny Brazilian tree, Chorisia speciosa.

Origin of vegetable silk

First recorded in 1850–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for vegetable silk

vegetable silk

noun
  1. any of various silky fibres obtained from the seed pods of certain plantsSee also kapok
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012