I turned the car key and started the engine.
A single key on a musical instrument or computer keyboard.
ピアノのキーを一つずつ押してみた。
I pressed each piano key one by one.
Musical key; the tonal center of a piece. Often used with 調.
See also: 調
この曲はハ長調のキーで書かれている。
This piece is written in the key of C major.
key (to solving something); clue
Figurative key or crucial piece of information for solving a problem or mystery.
事件解決のキーは彼の証言だった。
The key to solving the case was his testimony.
noun-modifying (irregular)
key (person, point, etc.); most important
Prenominal use meaning crucial or most important; often in compounds like キーパーソン or キーポイント.
彼はこのプロジェクトのキーパーソンだ。
He is the key person for this project.
彼女はパソコンのキーを叩いてレポートを書いている。
She's typing on the computer keyboard, writing a report.
This song's key is too high for me to sing.
It seems he holds the key to solving this case.
He's the key person in this project.
キー means a single key, whereas 鍵盤 refers to the entire set or row of keys.
Used especially for old-fashioned or shaped keys; in everyday counting, 個 is also common but not the characteristic counter.
keyboard
key word; key phrase; clue · keyword; search term; index term
keychain; key holder · key ring (encryption)
key person; important person
hero image; key visual
master key
key point; the key
key station; flagship station; leading station of a broadcasting network
keyway; key slot
Loanword from English 'key'.
primary key
original key (of a song)
candidate key
key input; keyboard input
key matching
protection key
modifier key
ENTER key