形容詞 needless:

1. unnecessary and unwarranted
   同義詞：gratuitous, uncalled-for

1. He got a large fortune when his father died, but trifled it away in only a few years of needless spending.
   父親去世時他得到一大筆財產(chǎn)，可僅僅幾年的時間就將這筆錢胡亂揮霍一空。
2. Needless to say, learning without thinking is useless.
   不用說，學而不思則罔。
3. Needless to say, he kept his promise.
   不用說，他信守了他的諾言。

need.less

adj.（形容詞）
Not needed or wished for; unnecessary.
不需要的：不需要的，不想要的；不必要的

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