manque

adjective[after a noun]2

1. •
   unable to fully realise one's ambitions; would-be
2. •
   Unfulfilled due to the vagary of circumstance, some inherent flaw or a constitutional lack.

   • “[…] and all things considered, I don't much regret that this affair with Miss Amory is manquée, though I wished for it once—in fact, all things considered, I am very glad of it.” — 1848