A term/phrase to imply that something is good, or to the extent of being excellent.
More commonly used by cadets of 148 Barnsley sqn.
Sounds better when said in a Yorkshire accent. No other accent can pull it off really.
Often confuses those who aren't in the know when you say an item of clothing is Gucci. So my advice is don't say it around those people; they would think you were dense/illerate.