Green’s Dictionary of Slang

1. (Irish) as an intensifier, complete, utter.

1879		C.J. Kickham Knocknagow 573: If he does not come home it will be a sore disappointment to me.
1886		R.L. Stevenson Kidnapped 97: Ye’ve made a sore hash of my brig.
1911		St. J. Ervine Mixed Marriage Act III: It’s the sore work, Mrs. Rainey.

2. (Irish, esp. juv.) good, great.

1996

(con. 1970) G. Moxley Danti-Dan in McGuinness Dazzling Dark (1996) I iv: ber.: There’s a back room in Kings though where you can pick your ring in private. cactus: Sounds sore.