Green’s Dictionary of Slang

(Irish) chat, conversation; also as v., to chat.

1825		T.C. Croker Fairy Legends and Traditions of the South of Ireland (1862) 85: Some people used to wink and look knowing when Felix was gostering. [Ibid.] 89: ‘Gostering,’ which occurs in the text, may be explained as boasting talk.
1833		W. Carleton Traits and Stories of Irish Peasantry III 370: ‘Give no gosther, Sam,’ replied Phelim, ‘but send round the bottle.’.
1856		Leicester Jrnl 1 Aug. 4/1: Don’t coom gosterin’ here, — I can’t dew nothin sorry!
1910		P.W. Joyce Eng. As We Speak It In Ireland.
1914		Joyce ‘Ivy Day at the Committee Rooms’ Dubliners (1956) 124: I asked him again now, but he was leaning on the counter in his shirt-sleeves having a deep goster with Alderman Cowley.
1986		(con. 1930s) P. O’Farrell Tell me, Sean O’Farrell 67: A few of us were gostering around the fire in his house.
1994		(con. 1960s) G. Byrne Pictures in my Head 56: This usually took about two hours, allowing half an hour for gostering and slingeing.
1995		P. O’Keeffe Down Cobbled Streets, A Liberties Childhood 201: Will you girls hurry up and stop gostering.