ADJ.
bloody
VERB + ONNA
dole, know, put
ONNA + NOUN
'tween, i'm, mate, street
ADV.
then
contraction
On the.
"Next thing I know you're onna ground, bloody. I don't know what come over me. You goin' out?" Lenny asked.
Mal said, “How you doing then?” “Me? I'm onna dole, mate. I'm onna street.”
On a.
I bin tole ta put a rag onna stick 'tween huh teef so she not bite huh tung.
i Register
In some senses, onna is marked as colloquial. Watch for register when choosing this word.