UNSUCCESSFUL
abortive, stillborn, unsuccessful
(adjective) failing to accomplish an intended result; “an abortive revolt”; “a stillborn plot to assassinate the President”
unsuccessful
(adjective) not successful; having failed or having an unfavorable outcome
Source: WordNet® 3.1
Etymology
Adjective
unsuccessful (comparative more unsuccessful, superlative most unsuccessful)
Failed, not successful.
Antonyms
• successful
Source: Wiktionary
Un`suc*cess"ful, a.
Definition: Not successful; not producing the desired event; not fortunate;
meeting with, or resulting in, failure; unlucky; unhappy.
– Un`suc*cess"ful*ly, adv.
– Un`suc*cess"ful*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition