real jam

Noun

 * 1)  Anything exceptionally good.
 * 2) * George Augustus Sala, The Story of Jack the Painter, in 1863, Tales and Essays (volume 3, page 10)
 * It's real jam, that little pictur his [sic]. I wouldn't mind springin' the price to a century. There! Shall I send my boy round to tell him so?