a. 无用的, 无益的

[法] 无益的, 无用的

[ adj ]
unproductive of success
<adj.all>
a fruitless searchfutile years after her artistic peak
a sleeveless errand
a vain attempt

Bootless \Boot"less\, a. [From {Boot} profit.]
Unavailing; unprofitable; useless; without advantage or
success. --Chaucer.

I'll follow him no more with bootless prayers. --Shak.
※ -- {Boot"less*ly}, adv. -- {Boot"less*ness},
n.