Chivalry

Chivalry is the name of an ability or set of abilities available to the Paladin job class in various games of the series.

Final Fantasy XI
Chivalry is a merit ability for Paladins in Final Fantasy XI. It allows them to convert their TP into MP.

Final Fantasy Tactics Advance
Chivalry is the name of the skillset used by Paladins. It consists mostly of defensive and supportive actions, but also with a couple Holy attacks.

Final Fantasy Tactics A2: Grimoire of the Rift
Chivalry is again a skillset learned by Paladins. It contains most of the same abilities as in the game's predecessor.