definition of
[failing]

[1] #1 failing n. [weakness] a flaw or weak point; "he was quick to point out his wife's failings". wn

[2] #2 failing s. below acceptable in performance; "received failing grades". wn

[3] #3 failing n. [flunk] failure to reach a minimum required performance; "his failing the course led to his disqualification"; "he got two flunks on his report". wn