Definition from Wiktionary, the free dictionary
|hold in mouth; bite; (Cant.) no/not||
that; the above-mentioned; most likely; to deserve; should; ought to; owe
From the negation particle 唔 and the character 該／该 (“should”), literally meaning "[this] should not [be done]", saying that what the other had done was not necessary or it was very kind of them to have done this.
- excuse me (to get attention)
- thank you