What Is a Grook

It could be a granny who is a crook, or a gigantic fish caught down by the brook, a hearty german stew you like to cook, or how about a great person you read about in a book. or possibly the theory of gravity when you unhook, or the gravitational pull when you get a certain look, or maybe that lost packet of gravy found in the nook? I guess its mostly used for poetry but I thought I'd take a second look. 2-5-17