one that got away

the one who/that got away

Someone or something that one regrets having lost. You're never going to be happy in your love life if you spend the rest of your days pining over the one who got away. He still talks about that failed deal as the one that got away.
See also: away, one, that, who
Farlex Dictionary of Idioms.

one that got away

Fig. the big fish that got away, especially as the subject of a fisherman's story. The one that got away is always bigger than the one that got caught.
See also: away, one, that
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • (one) could use (something)
  • drive (one) out of office
  • force (one) out of office
  • force out of office
  • give (one) (one's) head
  • give head
  • give somebody their head
  • give someone their head
  • cooking for one
  • 1FTR
References in periodicals archive
JUSTIN Rose has decided to count his blessings instead of agonising over the one that got away as he targets a second US Open title at Erin Hills.
"So it is one that got away for sure, but I think that's part of the game so I'm fully accepting of it.
Rose refuses to dwell on the one that got away; GOLF
"You just have to say it was the one that got away and we must now work towards the next one not getting away.
RUGBY: SIX NATIONS CHAMPIONSHIP: DON'T SLAM DUNC; Scots won't kick Hodge when he's down