Villagers' Attack, Speed, and Hit Points increased
Jihad is a technology in Age of Empires. It is researched at the Temple, and increases the abilities of Villagers in combat and movement speed, but at the price of reducing their gathering abilities by 50%.
As with many of the techs and themes in Age of Empires, this tech name is somewhat inconsistent with historical factuality, as Jihad in Arabic literally means "struggle", viz (in Islam) "striving or exerting oneself for God". In the current Middle East, it is also a religion-neutral first name.
The icon is very similar to the icon later used to represent the Monastery in Age of Empires II. However, the Monastery icon lacks the blood present on Jihad's icon.