fruitless
adj.adj. failing to produce any useful results. You use this to describe work or efforts that do not achieve what you wanted.
adj. producing no useful or desired results; unsuccessful or unproductive. Often describes abstract efforts, searches, or discussions.
The search for the missing keys was fruitless.
After hours of fruitless negotiation, both sides left the meeting without reaching an agreement.
The scientists spent years on a fruitless quest for a cure before a sudden breakthrough in a different field changed their entire approach.
Inherited from Middle English fruytles; equivalent to fruit + -less. Compare Middle English withouten fruyt (“fruitless”, literally “without fruit”).
Often follows a linking verb like 'prove' or 'remain' (e.g., 'the search proved fruitless').