Failing (adjective)
definition:
below acceptable in performance
example:
"received failing grades"
Failing (noun)
definition:
failure to reach a minimum required performance
example:
"Failing the course had led to my disqualification."
Synonyms
FlunkFailing (noun)
definition:
a flaw or weak point
example:
"They was quick to point out my failings."
Synonyms
Weakness