a flannel-covered surface to which other flannel pieces, as letters of the alphabet, numbers, etc., adhere merely by contact, used mainly in schools as a visual aid.
Origin of flannelboard
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
flannelgraph (ˈflænəlˌɡrɑːf, -ˌɡræf)
a visual aid used in teaching consisting of a board covered with flannel to which pictures, diagrams, etc will stick when pressed on
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