failing
US /ˈfeɪ.lɪŋ/
UK /ˈfeɪ.lɪŋ/

1.
a weakness or fault in character
:
•
Despite his many talents, his biggest failing was his inability to manage money.
•
Everyone has their own little failings.
1.
used to indicate the failure of something to happen or be done
:
•
Failing that, we'll have to find another solution.
•
He promised to help, failing which I would be on my own.
1.
declining in strength or effectiveness; deteriorating
:
•
His eyesight has been failing for years.
•
The old bridge is failing and needs urgent repairs.