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.