not for (a) lack of trying

not for (a) lack of trying

Despite putting forth a significant amount of effort or energy. A: "So, did he get you to go on a date with him?" B: "No. Not for lack of trying, mind you." I'm sorry your team lost, but it wasn't for a lack of trying!
See also: lack, not, of, trying
Farlex Dictionary of Idioms.

not for lack/want of ˈtrying

used to say that although somebody has not succeeded in something, they have tried very hard: He’s had no success in finding a job, though not for lack of trying.
See also: lack, not, of, trying, want
Farlex Partner Idioms Dictionary
See also:
  • from this/that day forth
  • break a sweat
  • from that day/time forth
  • not rest on (one's) laurels
  • not rest on your laurels
  • go forth
  • set forth
  • do or die
  • do or die, to
  • stretch forth