(grade 1 “Kyōiku” kanji)
/ki2/ invalid IPA characters (2): [kɨ], from [ki]
From Old Japanese. Likely developed from fusion of older form ko + い (i, emphatic nominative particle), similar to the sound changes at work in 神 in the shift from kamu to kami.
Now the modern Japanese word.
木 (hiragana き, rōmaji ki)
- a tree; a shrub
- wood, timber, lumber
- (graph theory, computer science) a tree (data structure)
- 猿も木から落ちる (saru mo ki kara ochiru): “even monkeys fall from trees”, i.e. even experts make mistakes
Old Japanese. Possibly an intermediate form. Obsolete in modern Japanese, and never found in isolation; remains in certain place names. Even in ancient times, its use was apparently limited to eastern dialects.
木 (hiragana け, rōmaji ke)
- a tree
麻都能氣乃 奈美多流美礼波 伊波妣等乃 和例乎美於久流等 多々理之母己呂 
- 松の木の 並みたる見れば 家人の 我れを見送ると 立たりしもころ
まつのけの なみたるみれば いはびとの われをみおくると たたりしもころ
Matsu no ke no / namitaru mireba / iwabito no / ware o miokuru to / tatari shi mokoro
- Looking at the pine trees all in a row, they were just like the people from the household standing to see me off
/ko2/ invalid IPA characters (2): [kə], from [ko̞]
Old Japanese. Likely the original form. Obsolete in modern Japanese, and never found in isolation; only found in compounds and certain idioms.
木 (hiragana こ, rōmaji ko)
- a tree
- 木高し (こだかし, kodakashi)
- 木霊 (こだま, kodama)
- 木隠れ (こがくれ, kogakure)
- 木陰 (こかげ, kokage)
- 木の葉 (このは, konoha)
- 木立 (こだち, kodachi)
From Middle Chinese 木 (muwk). The goon reading, so likely the original borrowing. Compare modern Cantonese 木 (muk6).
木 (hiragana もく, rōmaji moku)
- a tree
- short for 木曜日 (Mokuyōbi): Thursday
- When written in romaji, often capitalized as Moku.
- wood grain
- Often written 杢.
From Middle Chinese 木. The kan'on reading, so likely a later borrowing. Compare literary Min Nan 木 (bo̍k).
木 (-na inflection, hiragana ぼく, rōmaji boku)
- (derogatory) wooden, as of a person's character or behavior
- (derogatory) wooden, as of a person's mental abilities: blockheaded, stupid, dimwitted
木 (hiragana ぼく, rōmaji boku)
- a tree; more specifically, a living tree
- the bent and gnarled trunk or roots of an old tree
- wood, lumber
- something made of wood
- in ancient China, a wooden musical instrument