Failing, n.
1. A failing short; a becoming deficient; failure; deficiency; imperfection; weakness; lapse; fault; infirmity; as, a mental failing. And ever in her mind she cas about For that unnoticed failing in herself. Tennyson.
2. The act of becoming insolvent of bankrupt.
Syn. -- See Fault.
Shades of meaning
Fernald lists failing only as an antonym, under healthy.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given