- a device fixed to the top of a violin or viola to provide a firm rest for the player's chin.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for chin rest
One should use a chin-rest to prevent perspiration from marring the varnish.
I use no chin-rest on my Guadagnini simply because I cannot find one to fit my chin.