ガツリ (gatsuri)

My students taught me this--ガツリ basically means めちゃ, or very, really. 

For example, "I really want to eat yakiniku!"= 焼肉（を）ガツリ食べたい！(Yakiniku gatsuri tabetai!)

It may be that some younger people use this term a bit different from middle-aged/older people.  My college students taught it to me, and it came about like this:  as a writing activity, I asked them to write letters to their older, future selves.  (This was in conjunction with watching a movie in which the main characters record a video for their older selves; I was trying to give my students a chance for a similar experience.)  As the class sat quietly, contemplating the letter they were about to write, some of them started to ask one another about how old were the future selves to which they were writing.  Some of them were writing to their forty-year-old selves, some a little older.  But one of them said that she wanted to be ガツリおばあちゃん (gatsuri obaachan), which was her term to signify a really old lady.

When I asked around about the gatsuri obaachan usage, most (including high school and college students) said that it sounded a little weird.  Basically, they said that gatsuri is used as an adverb, e.g. gatsuri ikitai (I really want to go), or gatsuri mitai (I really want to see it).