1. delusive Vain (L. vanus, empty) keeps the etymological idea through all changes of meaning; a vain endeavor is empty of result, or of adequate power to produce a result, a vain pretension is empty Synonyms: vain, abortive, futile, shadowy, unsatisfying, baseless, idle, trifling, unserviceable, bootless, inconstant, trivial, unsubstantial, deceitful, ineffectual, unavailing, useless, delusive, nugatory, unimportant, vapid, empty, null, unprofitable, visionary, fruitless, profitless, unreal, worthless Antonyms: adequate, effective, powerful, solid, useful, advantageous, efficient, profitable, sound, valid, beneficial, expedient, real, substantial, valuable, competent, potent, serviceable, sufficient, worthy