1. lunatic
2. madman
Relative explainations:
<loony> <loco> <kook> <nutcase> <maniac> <nut(cover)> <crackpot> <crackbrain> <ding-a-ling> <bedlamite> <psychotic> <nutter> <the insane> <looney> <luny>
Examples:
1. 如果妳告訴他們妳要乘木筏橫渡太平洋，他們壹定會認為妳是個瘋子。
They must think you are a madman if you tell them you want to cross the Pacific on a raft.
2. 有個瘋子破壞了那幅畫，在上面劃了許多窟窿。
A madman mutilated the painting by cutting holes in it.
3. 我真不了解他到底是怎樣的人；壹會兒正常，壹會兒又像個瘋子。
I really don't know what kind of man he really is; on one occasion, he is normal, and on another, he acts like a lunatic.
4. 沒有人想聽瘋子講話。
No one wanted to listen to a madman.
5. 這種令人驚駭的謀殺純粹是瘋子的行為.
This dreadful murder is surely the act of a madman.
6. 那個瘋子開車開得太快了.
That maniac drives far too fast.
7. 他開汽車像個瘋子--不定哪天就得撞死.
He drives like a nut he'll kill himself one day.