Hillel

The phrase Hallelujah has the same root.

Hillel is also known in Jewish mythology as the name of the chief angel who rebelled against God and was thrown out of heaven - better known as Lucifer.
His full name was Hillel Ben-Shachar - "Hillel son of the dawn". The morning star (also called Lucifer) is called "Kochav Ben-Shachar" in Hebrew.

The reference to Lucifer above is a wrong assumption. First of all, "the morning star" is mentioned in the passage by Isaiah, and the controversy comes from the word HYLL (there spelled Het, yod, lamed, lamed Heyel), however Hillel is spelled het, lamed, lamed (no yod!). In addition, in the passage Isaiah is literary talking about morning star. In medivel times, Lucifer (which comes from Latin) meant "morning star or the planet Venus", only later the writer called Milton in his novel created a character who was a Satan named "Lucifer". Thus the name "Hillel" has absolutely nothing to do with "Lucifer".
Here is one of the online sources:
http://www.kjvonly.org/doug/kutilek_notes_on_lucifer_pr.htm