here is a possible derivation, if it is from Irish it would have the spelling as in the first word 'Broad with Broad, Slender with Slender' remember

seadhgosa, segosha, segasha add/view comments (0)

// n. pleasure, joy, delight; 'Me ould segosha' < Ir. seaghais n. (genitive singular: seaghsa or seaghaise, cf. Ir. seaghaiseach, pleasant, joyful. 'Come over here to me, me old seadhgosa, it's been a long time since I've seen you'. This word has attracted many fanciful and improbable explanations (e.g, the Irish phrase 'Seo dhuit é' = Here, take it) because of its literary associations, e.g., it is used by James Joyce in F.W., 215.12: "Ah, but she was the queer old skeowsha anyhow, Anna Livia, trinkettoes".