What's the τερπι- part of τερπικέραυνος?

Greek Homeric Greek and Early Greek Poetry
1

Iliad 1.419 says

τοῦτο δέ τοι ἐρέουσα ἔπος Διὶ τερπικεραύνῳ

LSJ (in its various forms) says it’s τερπι+κέραυνος – delighting in thunder, and I know the κεραυνός part but what’s τερπι? I can’t find anything on it. Does it ever appear elsewhere, by itself or as a prefix?

2

http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dte%2Frpw

3

Thanks!

I haven’t been able to figure out how to search the Perseus LSJ page for just a fragment of a word. Better yet, if there were an online page-by-page version of the whole lexicon (or either of its abridged versions) that would be wonderful…