忙しい

Derived from verb 急ぐ (isogu, “to hurry, to rush, to hasten”).^[1][2][3]

First attested in a text from 850.^[4]

By one analysis, this is the verb's 未然形 (mizenkei, “incomplete or irrealis form”) 急が (isoga) plus the adjectivizing suffix しい (-shii, “having that kind of quality”, classical terminal form -shi).

Alternatively, may be derived from the causative. The classical terminal form of the adjective is identical to the classical continuative or infinitive form of the causative verb, which was used in certain constructions to conclude sentences.

• 急ぐ (isogu, “to rush, to hurry”) → 急がす (isogasu, “to cause to rush, to cause to hurry”) → 急がし (isogashi, “having the quality of causing one to rush or hurry”)

• (Tokyo) いそがしい (Nakadaka – )^[2][5][6]
• IPA^(key):

忙(いそが)しい • (isogashii) -i (adverbial 忙(いそが)しく (isogashiku))

1. busy

   Antonym: 暇 (hima)

   彼(かれ)はいつも忙(いそが)しいことを言(い)い訳(わけ)にしている。

   Kare wa itsumo isogashii koto o iiwake ni shite iru.

   He always uses the excuse that he is too busy.

   • c. 1001–1014, Murasaki Shikibu, Genji Monogatari (Otome), text here:

     大(おお)殿(との)も、かやうの御(お)遊(あそ)びに心(こころ)止(と)めたまひて、いそがしき御(ご)政(せい)事(じ)どもをば逃(のが)れたまふなりけり。

     Ōtono mo, kayō no o-asobi ni kokoro tometamaite, isogashiki go-seiji domo o ba nogaretamau narikeri.

     The lord would also kept his attention on this kind of pleasure, and escape from all his busy governmental duties.

2. restless, fidgety

*⟨sepasi⟩ → /seɸaɕi/ → /sewaɕiki/ → /sewaɕiː/

Cognate with 狭い (sebai), older form of 狭い (semai, “adjective, lacking in space”),^[1] expanding on the meaning towards “lacking in time”.

First cited to a text from 1020.^[1]

• (Tokyo) せわしい (Nakadaka – )^[2]
• IPA^(key):

忙(せわ)しい • (sewashii) ^{←せはしい (sefasii)?}-i (adverbial 忙(せわ)しく (sewashiku))

1. busy, hurried
2. restless, fidgety

• 忙(せわ)しない (sewashinai)

• 忙(せわ)忙(せわ)しい (sewasewashī)

• 2002, Ineko Kondō; Fumi Takano; Mary E Althaus; et. al., Shogakukan Progressive Japanese-English Dictionary, Third Edition, Tokyo: Shōgakukan, →ISBN.