Futility

fu·tile

 adj \ˈfyü-t^əl, ˈfyü-ˌtī(-ə)l\

Definition of FUTILE

1

: serving no useful purpose : completely ineffective

2

: occupied with trifles : frivolous

fu·tile

   [fyoot-l, fyoo-tahyl] 

adjective

1.

incapable of producing any result; ineffective; useless; notsuccessful: 
Attempting to force-feed the sick horse wasfutile.

2.

trifling; frivolous; unimportant.

fu·tile  (fytl, fytl)

adj.

1. Having no useful result.

2. Trifling and frivolous; idle: the futile years after her artistic peak.

futile·ness n.

Synonyms: barren, bootless, fruitless, unavailing, useless, vain
These adjectives mean producing no result or effect: a futile effort; a barren search; bootless entreaties; 
fruitless labors; an unavailing attempt; a useless discussion; vain regrets.

Antonym: useful