名詞 killer:

1. someone who causes the death of a person or animal
   同義詞：slayer
2. the causal agent resulting in death
   同義詞：cause of death
3. a difficulty that is hard to deal with
4. predatory black-and-white toothed whale with large dorsal fin; common in cold seas
   同義詞：killer whale, orca, grampus, sea wolf, Orcinus orca

1. The killer stabbed him with a knife/stabbed a knife into him.
   兇手用刀刺他。
2. Police are baffled as to the identity of the killer.
   警方不解兇手是誰(shuí)。
3. The net result of the long police investigation is that the identity of the killer is still a complete mystery.
   警方經(jīng)長(zhǎng)時(shí)間調(diào)查，結(jié)果兇手的身分仍全然不知。
4. The police chief spoke of his determination to catch the killer.
   警長(zhǎng)談到他決意要抓獲兇手。
5. Hitler is a notorious killer.
   希特勒是一個(gè)臭名昭著的劊子手。

kill.er

n.（名詞）
One that kills:
殺人者：
例句：
a disease that was a killer of thousands; a killer of new ideas.
殺死了千萬(wàn)人的疾??；殺死新思想的殺手

Slang Something that is extremely difficult to deal with or withstand:
【俚語(yǔ)】 鬼門關(guān)：極難對(duì)付或抗拒的東西：
例句：
an exam that was a real killer.
真正是鬼門關(guān)的考試