Definition of onliest in English:

onliest

adjective

informal
  • ‘you're the onliest man I've seen who has everything’
    non-standard form of only (adjective)
    • ‘Blues legend Son House, for example, says the penetrating pain of betrayal in sexual relationships is ‘the onliest thing the blues is.’’

Pronunciation

onliest

/ˈəʊnlɪəst/