Dictionary.com
definitions

bass clef

[beys]
noun Music.
  1. a symbol placed on the fourth line of a staff to indicate that the fourth line of the staff corresponds to the F next below middle C; F clef.

Origin of bass clef

First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for bass clef

bass clef

noun
  1. the clef that establishes F a fifth below middle C on the fourth line of the staffSymbol: Also called: F clef
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