(Cant.) an interjection used to berate someone/an expression said in an attempt to 'counteract' or 'cancel out' the effect when someone else has said something unlucky or unpleasant
Definitions (粵典–words.hk)
感嘆詞
講咗唔吉利嘅嘢之後用該字,以表示唔吉利的東西唔會靈驗 (used to drive away bad luck, esp. when the speaker hears sth inauspicious) similar to the use of "touch wood" but said by another person
啋!新年流流講埋啲噉嘅嘢㗎!
啋!新年流流讲埋啲噉嘅嘢㗎!
coi1! san1 nin4 lau4 lau4 gong2 maai4 di1 gam2 ge3 je5 gaa3! Touch wood! Why are you saying such (inauspicious) things in the New Year?
Definitions (Wiktionary)
character, Cantonese
interjection used to berate someone when something inauspicious or unpleasant is said; touch wood