(my source is the hebrew wikipedia)
Eyal comes from the bible (old testament) - Psalmi chapter 88 line 5.
I am reckoned with those who go down to the pit;
I am like a warrior without strength.
strength is a translation of Eyal.
it also means vitality (in hebrew - On)
from what my parents told me, it also means courage
(Sent from: Eyal)