Definition of "roistering"

[H]e could look on with an eye of kindness at the lookers-on too; at the roystering youth bent upon enjoyment, and here taking it […]

1848 November – 1850 December, William Makepeace Thackeray, chapter 47, in The History of Pendennis. […], volumes (please specify |volume=I or II), London: Bradbury and Evans, […], published 1849–1850

Merry Mansions Sunday night, with loud parties in the distance. Matilda said she was going to have a good time at some heaven. And George Smith sat alone staring across the room. And out the window for a bit, at a roistering gathering of folk across the street. A city full of fathers with gathered arms of presents to give and get, this complicated time of year.

1963, J P Donleavy, A Singular Man, published 1963 (USA), page 86