Used by the speaker talking about themselves to others to emphasise the fact that they had better do something, usually a task or a chore that they are not keen on doing.
Spoken with a cut accent... Betta - neye
Can be used with Bettado Bettenyou see other definitions
Spelling is traditionally open to interpretation
Clive "I had better go to the shops and get some more Hobnobs, Bettaneye"
Maude "Yes, you Bettado, Bettenyou"