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(shí)他得到一大筆財(cái)產(chǎn)，可僅僅幾年的時(shí)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(xué)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）