a fortiori a fortiori /ə ˌfɔrʃiˈoʊraɪ/

adverb

1. () With greater reason; for a still stronger, more certain reason  ( a fortiori )
   with greater reason; for a still stronger, more certain reason
    If you are wrong then, a fortiori, so am I
   if you are wrong then, a fortiori, so am I