tenor clef

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The C clef positioned to indicate that the fourth line from the bottom of a staff represents the pitch of middle C.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun music a musical clef that is higher than the bass clef and lower than the alto clef where the A that is a third lower than middle C is the center line

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a clef that puts middle C on the fourth line of the staff; used for writing music for bassoons or cellos or tenor horns