UNSUCCESSFUL Meaning of UNSUCCESSFUL in English a. 1.Unavailing, ineffectual, abortive, fruitless, bootless, profitless, vain, futile, in vain.2.Luckless, unfortunate, unlucky, unprosperous, ill-starred, ill-fated, unhappy. Soule. Dictionary of English synonyms. Словарь английских синонимов. 2012