crown it all

crown it all (third-person singular simple present crowns it all, present participle crowning it all, simple past and past participle crowned it all)

1. (Britain) To be the final, or last-mentioned, event or occurrence in a series of particularly favourable / fortunate or unfavourable / unfortunate events.
   • 1960 October, P. Ransome-Wallis, “Modern motive power of the German Federal Railway: Part Two”, in Trains Illustrated, page 611:

     A lovely crisp exhaust: a feeling of almost unlimited power combined with complete freedom of running: and, to crown it all, a most melodious and wholly American chime whistle—these were my immediate impressions as we stormed rapidly out of Göttingen, intent on winning back some of the lost time.

   Synonyms: cap it all, top it off

• “to crown it all”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “crown it all” in the Cambridge English Dictionary, Cambridge: Cambridge University Press.
• “to crown it all” (US) / “to crown it all” (UK) in Macmillan English Dictionary.