of no avail—(predic.) useless; unsuccessful (also: of no effect):
- All their efforts to save him from his folly were of no avail.
to no avail—(also: to no effect):
1. unsuccessfully; in vain:
- We pulled him out of the river and tried to revive him, but to no avail.
2. = of no avail:
- The interviewee didn’t arrive, and efforts to reach him via cell phone were to no avail.