noun / adjectival noun:

• sharpness Antonym: 鈍【どん】

noun:

• sharp weapon; blade
• fine soldier

noun:

• thorn; spine; prickle
• splinter (esp. lodged in one's flesh); hard sharp item (esp. lodged in one's throat, e.g. fish bone)
• biting words

noun:

• the tip of an edged instrument
• sharp words; vicious character

expression / ichidan verb:

• to break off with (e.g. one's lover) - idiom
• to be sharp enough to cut one's skin (of a new banknote, etc.)

noun:

• cold desert; tundra

noun or verb acting prenominally / noun:

• sharp and sarcastic without ever acting lovestruck - manga slang ➜ つんでれ・つんつん

noun:

• convenience
• sharp-edged tool

ichidan verb / intransitive verb:

• to break; to snap; to be cut; to split; to crack
• to be injured
• to wear out; to be worn out
• to break; to burst; to collapse
• to wear off; to stop working; to go dead
• to expire (time limit, etc.); to run out; to become due
• to run out (of stock, etc.); to be exhausted; to be used up; to be sold out; to be out of
• to be broken off (e.g. of a relationship); to break up; to have severed ties; to be cut off; to be disconnected
• to cut well; to be sharp
• to be sharp-minded; to be keen; to be shrewd; to be quick-witted; to be able
• to be short of; to drop under (a certain figure); to beat (e.g. a record time)
• to dry off
• to curve; to veer
• to shuffle (cards)
• to get angry; to snap; to blow one's top; to lose one's temper; to flip - colloquialism ➜ キレる

auxiliary verb / ichidan verb:

• to be able to do completely - after the -masu stem of a verb - usually written using kana alone

noun:

• mirror with a mythical Chinese bird carved into the back ➜ 鸞鳥
• (in Japan) 9th note of the ancient chromatic scale (approx. A sharp) ［らんけい］ ➜ 夷則・十二律

noun:

• temple bell
• (in Japan) 7th note of the ancient chromatic scale (approx. G sharp) ➜ すい賓・十二律

noun:

• thin veneer; hasty preparation; knowledge or skill learned as a stopgap
• re-tempering a dull sword (so that it looks as if it's sharp, but is actually unusable) - orig. meaning