Futile (adjective)

1. Producing no result; ineffective; having no useful outcome.
2. Incapable of being carried out; impossible.
3. Lacking sense or meaning; pointless.

Origin:

Middle english, from latin futilis, from fusus, past participle of fundere to pour, from fusion-, fusio act of pouring — more at found.

Examples:

1. Their attempts to fix the problem were futile.
2. After several futile attempts, they finally succeeded.
3. His speech was futile and failed to convince anyone.
4. The futile search for a solution continued for days.
5. Their efforts to save the company were futile, it went bankrupt.