Zealous: Energy gain on hit: -?

What Does energy gain on hit mean?

Each time your are struck by a foe, your blue bar will gain in value.

Ok, thanks. I thought so, just wanted to be sure.

Actually it means every time YOU STRIKE AN ENEMY you gain 1 point energy.
With cyclone axe & a zealous axe, that can mean a lot of energy.

You don't want to keep zealous weapons equipped when you're not in battle as they also give -1 in energy regen (meaning that you regenerate 0.3 points of energy less per second).