Uncertain, but probably from closet (“private room; outhouse”), possibly compounded with lodge (“building”) and -ie (“forming affectionate diminutives”). Or simply onomatopoeic, from the sound of the flushing.
cludgie (plural cludgies)
- (Scotland slang) A lavatory: a room intended for urination and defecation.
- (Scotland slang) A toilet: a fixture intended for urination and defecation.
Originally and chiefly in the Glasgow area.
- ^ "cludgie, n." in the Oxford English Dictionary (2013), Oxford: Oxford University Press.