竹刀

Originally a clipping of 撓い竹 (shinaidake)[1]: 撓い (shinai, the 連用形 (ren'yōkei, “stem or continuative form”) of 撓う (shinau, “to bend”)) + 竹 (take, “bamboo”).

The kanji are an example of jukujikun (熟字訓).

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium. Particularly: “attestation of shinai?”)

• (Irregular reading)
• (Tokyo) し​ない [shíꜜnàì] (Atamadaka – [1])[1]
• IPA^(key): [ɕina̠i]

竹刀(しない) • (shinai) ^{←しなひ (sinafi)?}

1. bamboo sword used in martial arts such as 剣道 (kendō)

• → English: shinai

Compound of 竹(たけ) (take, “bamboo”) + 刀(かたな) (katana, “katana”). The katana of 刀 changes to gatana as an instance of rendaku (連濁).

• Kun’yomi
• (Tokyo) たけが​たな [tàkégáꜜtànà] (Nakadaka – [3])[1]
• IPA^(key): [ta̠ke̞ɡa̠ta̠na̠]

竹(たけ)刀(がたな) • (takegatana) 

1. katana with a bamboo blade; takemitsu
2. bamboo comb used to comb a horse's mane (Can we verify^{(in Nippo Jisho%7c%E7%AB%B9%E5%88%80%5D%5D +)} this sense?)

• (sword): 竹(たけ)光(みつ) (takemitsu)

From the on'yomi reading of the kanji. (Can this⁽⁺⁾ etymology be sourced?)

• On’yomi
• (Tokyo) ちくとー [chìkútóó] (Heiban – [0])[1]
• IPA^(key): [t͡ɕikɯ̟ᵝto̞ː]

竹(ちく)刀(とう) • (chikutō) ^{←ちくたう (tikutau)?}

1. katana with a bamboo blade; takemitsu
2. bamboo sword used in martial arts such as 剣道 (kendō); shinai