【Futile】 , 【vain】 ,  【fruitless】 ,  【bootless】 ,  【abortive】  all denote barren of result.

【Futile】  and  【vain】 parallel each other only when they imply failure to realize an immediate aim.

【Vain】  (see also  【VAIN】 1 ) usually implies little more than simple failure;  【futile】 may connote the completeness of the failure or the unwisdom of the undertaking.

Though both  【vain】  and  【futile】  may be applied to something contemplated but not yet tried,  【vain】  more often suggests a judgment based on previous experience and  【futile】 , one based on reasoning from self-evident principles.

【Fruitless】  is often interchangeable with  【vain】 . But its basic meaning makes it especially applicable to undertakings that entail long, patient, arduous effort and severe disappointment.

【Bootless】 , chiefly poetic, is especially applied to petitions or efforts to obtain relief.

【Abortive】 implies failure before plans are matured or activities begun.