Synonyms for Failing (same or very similar meaning)
WordNet sense 1 (a flaw or weak point):
weakness
WordNet sense 2 (unable to meet financial obligations):
failed
WordNet sense 3 (not successful; having failed or having an unfavorable outcome):
unsuccessful
WordNet sense 4 (not giving satisfaction):
unsatisfactory
WordNet sense 5 (failure to reach a minimum required performance):
flunk
From the ODE community, based on WordNet
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