What does this mean?

[L. Priest]

When you take a look at a THFs skills it says that it will learn a skill called "RESIST GRAVITY" i figured it meant to resist a spell called Gravity but when i went a looked through the Magic lists I found that there wasnt spell called Gravity, so now i have to ask what is Gravity and why are THFs resisting it:? LOL

[Jei]

it's a redmage's specific spell. also some enemies will have their special move which can heavied you.