Futility
Uselessness, Pointlessness
noun, な adjective
Nothing but burdensome. That's all you get out of doing this task. The futility of it is ridiculous. The uselessness is huge.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
言うだけ無駄だよ。フグは決して忠告には耳を貸さないんだから。
Just saying it is useless. Fugu never listens to advice.