Green’s Dictionary of Slang

(Irish) a surprise, usu. a disappointment, a letdown.

1995		A. Higgins Donkey’s Years 31: ‘A land’, or ‘a bit of a land’, meant an unexpected disappointment, a let-down.
1996		D. Healy Bend for Home 278: As the demented hairdresser in the film walked down the King’s Road she passed the Classic cinema in which I was sitting. I got an awful land. It was a special effect Polanski would have been proud of.
2017		L. McInerney Blood Miracles : ‘It gave Jiimmy a terrible land, finding you here’.