fruit ‧ less /ˈfruːtləs/ BrE AmE adjective
[ Word Family: noun : ↑ fruit , ↑ fruition , ↑ fruiterer ; adjective : ↑ fruitful ≠ ↑ fruitless , ↑ fruity ; verb : ↑ fruit ; adverb : ↑ fruitfully ≠ ↑ fruitlessly ]
failing to achieve what was wanted, especially after a lot of effort OPP fruitful
fruitless attempt/exercise
a fruitless attempt to settle the dispute
So far, their search has been fruitless.
—fruitlessly adverb