The Oxford Thesaurus An A-Z Dictionary of Synonyms - failing n.

1) weakness, shortcoming, foible, flaw, fault, defect, weak spot, blind spot, blemish, imperfection: Bigotry and prejudice are her most serious failings. --prep. 2) lacking, wanting, in default of, without, sans, in the absence of: Failing a favourable decision, we shall lodge an appeal.