As a verb failing
As a noun failing
is weakness; defect.
As a preposition failing
is if the preferred or prior option is not possible.
As an adverb incorrectly is
in an incorrect manner.
- His worst failing is his temper.
if the preferred or prior option is not possible
- A large proportion of the females employed in other firms are said to have signified their intention of going on strike, failing a settlement.