Definition of deffo in English:

deffo

adverb

British
informal
  • Definitely; certainly.

    ‘Tyler is by far the best—he should deffo win’
    • ‘He should deffo win.’
    • ‘Yeah - I'm deffo not a good ambassador for it though, I'm already trailing horribly.’
    • ‘I hate myself for saying it but I think they can deffo go all the way this year.’
    • ‘Jesper Olsen is deffo leaving after a punch up with Remi Moses the other day.’
    • ‘I liked that women were most deffo the heroes, and that they were allowed to be more than victims who just happen to get out alive.’

Origin

1990s: abbreviation.

Pronunciation

deffo

/ˈdɛfəʊ/