knives

n. tool with a thin sharp blade that is used for cutting

A knife is a sharp-edged (single or double edged) instrument consisting of a thin blade used for cutting and fitted with a handle. The knife can be used as a tool or a weapon. Considered by some to be one of the most useful tools of all time, its origins date as far back as two-and-a-half million years ago, as evidenced by the Olduwan tools.
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Noun
1. edge tool used as a cutting instrument; has a pointed blade with a sharp edge and a handle
(hypernym) edge tool
(hyponym) barong
(part-meronym) blade
(derivation) stab
2. a weapon with a handle and blade with a sharp point
(hypernym) weapon, arm, weapon system
(hyponym) bayonet
(part-meronym) point, tip, peak
(derivation) stab
3. any long thin projection that is transient; "tongues of flame licked at the walls"; "rifles exploded quick knives of fire into the dark"
(synonym) tongue
(hypernym) projection
Verb
1. use a knife on; "The victim was knifed to death"
(synonym) stab
(hypernym) injure, wound
(hyponym) poniard

(pl. )
of Knife
  

(n. pl.)
of Knife. See Knife.
  

(pl. )
of Pocketknife
  

ru2 dao1 ci4 xin1
Like being stabbed in the heart.
(No further explanation)

sha1 ji1 yan1 yong4 niu2 dao1
Why use and ox-cleaver to kill a chicken?
Performing a minor feat with unnecessary great effort. Why break a butterfly on the wheel? Using a steam-hammer to crack nuts. Alternative form: 割鸡焉用牛刀 (ge1 ji1 yan1 yong4 niu2 dao1).

xiao4 li3 cang2 dao1
Hiding a dagger behind a smiling face.
To be outwardly friendly and kind, but inwardly treacherous and ruthless.