Depending on context, it's either referring to a grapple or, more likely, the Hold Person spell, which paralyzes.
I look up the creature on pfsrd.com. It has an ability that holds you where you stand, and you can't move until making a fort save. I am assuming that is it, but it could also be something like hold person which is not good because I think that ability is an AoE.
I never thought of looking at the creature--I didn't realize it would be open content, since it's 3rd party.
Having read it, I am now 90% positive it refers to Hold Person (i.e. peralysis). I am aware that it's AoE, but it does require a full round action on the part of the elemental, so I kind of understand, I guess. I don't know, nobody said 3rd party material was necessary any good.