dunnodun‧no /ˈdʌnəʊ $ -noʊ/ 
a way of saying ‘I don’t know’. Some people think that this use is not correct English: 
‘Do you want to come?’ ‘I dunno, I might.’
a way of saying ‘I don’t know’. Some people think that this use is not correct English: ‘Do you want to come?’ ‘I dunno, I might.’