In the context of monster hunter world which the meme is referencing it is a skill that raises the character’s tolerance for attacks that would otherwise flinch them out of their animations. For singleplayer it is functionally worthless because all monster attacks of note cause knockdowns or heavy stagger that is mitigated by other skills entirely. The only use is in multiplayer where certain spammy weapons can stagger other weapons, but due to the way that monster weaknesses are distributed all the spammy weapons (which happen to be mostly immune to getting staggered by other spam weapons by default) should be going for a different part of the monster, leaving some hitzones for the likes of hammer and company.