Green’s Dictionary of Slang

(Irish) a general derog., an incompetent.

1988		R. Doyle Commitments 103: A spa could paint better than tha’, he told Jimmy.
1991		R. Doyle Van (1998) 368: Let’s face it lads. They were spas.
2000		P. Howard Miseducation of Ross O’Carroll-Kelly (2004) 61: She is so embarrassed [...] and she’s probably making a total spa of herself.