treble clef

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A symbol indicating that the second line from the bottom of a staff represents the pitch of G above middle C. Also called G clef.

Wiktionary

1. n. music a symbol showing that the second line from the bottom of the stave represents the G above middle C

WordNet 3.0

1. n. a clef that puts the G above middle C on the second line of a staff