形容詞 pointless:

1. not having a point especially a sharp point
   同義詞：unpointed
2. serving no useful purpose; having no excuse for being
   同義詞：otiose, superfluous, wasted
3. lacking import
   同義詞：purposeless, senseless

1. A pointless dispute over niggling details.
   在瑣碎小事上的一次無禮爭吵
2. Pointless attempts to rescue the victims of the raging fire.
   試圖將熊熊大火中的遇難者救出的徒勞舉動
3. It's pointless trying to keep your friendship secret it's common knowledge already.
   你們無謂將友情保密--其實已盡人皆知了。
4. We had fallen so far behind that it seemed pointless continuing.
   我們已經(jīng)落在後面很遠，繼續(xù)下去似乎沒有什麼意義。

point.less

adj.（形容詞）
Lacking meaning; senseless.See Synonyms at meaningless
缺乏意義的；無意義的參見 meaningless
Ineffectual:
無效果的：
例句：
pointless attempts to rescue the victims of the raging fire.
試圖將熊熊大火中的遇難者救出的徒勞舉動

【引伸】
point.lessly
adv.（副詞）
point.lessness
n.（名詞）