useless; pointless; ineffectual; hopeless
The doctor frankly told him that his cancer had now reached the terminal stage, and that any further treatment would be futile.
futilis (vain, worthless, futile) (Latin)
futile is not fertile. hence not fruitful futile sounds like foot oil. spending 1000$ on foot oil is WASTE. and UNPRODUCTIVE bcoz even then hair will not grow on your foot. haha seems funny but works.