I checked Wiktionary's category of Wu interjections [1] and 呵 (Wiktionary romanization hu (T1), Sinological IPA /hv̩ʷ⁵³/) "5. Exclamation particle for expressi

I checked Wiktionary's category of Wu interjections [1] and 呵 (Wiktionary romanization hu (T1), Sinological IPA /hv̩ʷ⁵³/) "5. Exclamation particle for expressing surprise." [2] seems like it would fit their loose pattern. (Although it might be that this particular meaning isn't actually used in Shanghainese.) [1] https://en.wiktionary.org/wiki/Category:Wu_interjections https://en.wiktionary.org/wiki/Category:Wu_interjections [2] https://en.wiktionary.org/wiki/%E5%91%B5 https://en.wiktionary.org/wiki/%E5%91%B5