Green’s Dictionary of Slang

(UK society) disorganized, chaotic, less than smart.

1982		Barr & York Sloane Ranger Hbk 158: jungly adj. Disorganised, unsmart. ‘Went to a jungly hunter trial last weekend.’.
1982		N.Y. Rev. of Books 7 Oct. 🌐 Mrs. Ras Mohun’s stock response to behavior that displeased her was to say, ‘Don’t be a jungly boy,’ or ‘That’s what jungly boys do.’.