General synonyms:
* Futile
* Useles
* Meaningless
* Worthless
* Insignificant
* Fruitless
* Vain
* Absurd
* Silly
* Frivolous
* Nonsensical
Words emphasizing lack of purpose:
* Aimless
* Unproductive
* Unnecessary
* Superfluous
* Redundant
Words emphasizing futility:
* Hopeless
* Despairing
* In vain
* To no avail
* Dead end
Words emphasizing lack of value:
* Trivial
* Minor
* Unimportant
* Negligible
* Paltry
Words with a more negative or critical connotation:
* Idiotic
* Stupid
* Moronic
* Inane
* Ludicrous
The best word choice will depend on the specific situation and the desired effect. For example, "futile" is more formal than "pointless" and suggests a greater sense of hopelessness. "Nonsensical" implies that something is illogical or irrational.
Consider the context and choose the word that best captures the intended meaning.