I'm trying to read more, in all of my languages, and my current Japanese book is the novelization of 君の名は。 or Your Name. I came across this word I didn't know towards the end of the book, and then got into a bit of a look-it-up rabbit hole. The sentence in question (underlines added by me):

三葉は自分の頭にくるりと組紐を回す。カチューシャのように縦に巻いて、左耳の上でちょうちょ結びにする。

Mitsuha wraps the plaited cord around her head, so that it resembles an Katyusha [headband, or "Alice Band"] lengthways, and makes a butterfly knot [bow knot] above her left ear.

That's my rough translation of the sentences from 君の名は。(Your Name.) by 新海誠 (Makoto Shinkai), published by 角川つば文庫 (Kadokawa Tsubasa Bunko), 2016. p. 202. The bracketed bits are what we would say in English (or, in the case of "Alice Band," what you get looking the word up on jisho.org or in JMdict); the underlined bits literally translate the actual Japanese. I was amused by the imagery of the butterfly knot, but Katyusha, or "kachuusha" as it's pronounced in Japanese, is what really caught my eye. It didn't sound like something that derived from English, as many katakana words are, so I was curious about its meaning and origin. It's the sort of word that can't be found in my smaller Japanese dictionaries like the Shin Meikai; one has to break out the heavyweights (emphasis on heavy) for this sort of word.

Katyusha has a pair of entries in my copy of the 3rd edition of the massive and tiny-fonted 大辞林 (Daijirin) dictionary; the first of these (below) covers the headband.

カチューシャ 2 〔大正時代に松井須磨子が演じた「復活」の女主人公の名から〕髪飾りの一。弧の形で、前方から両耳までの髪をおさえるもの。布をかぶせたものやプラスチック製のものがある。

Katyusha 2 (From the name of the female protagonist played by Sumako Matsui in the Taisho-era "Resurrection") A hair ornament. An arc-shaped object which pins the hair down from the front to both ears. Can be cloth covered or manufactured from plastic.

My copy of the 5th edition of the 広辞苑 (Kōjien) also has two entries, one for the headband and one for the character. Here's the headband one:

カチューシャ (大正初期上演の「復活」で、主人公カチューシャがつけたことから）ヘアーバンドの一種。丸く曲げて弾力性を持たせた細長い金属板・プラスチック板。また、それを布で被ったもの。

Katyusha (From the thing worn by the protagonist Katyusha in the Taisho initial performance of "Ressurection) A type of hairband. A long thin metal plate or plastic plate with elasticity bent in a curve. Also, that object covered in cloth.

And how about that "Alice Band" definition given in JMdict? I think just plain ol' "headband" is what I would commonly call the object described by the Japanese dictionary entries above, but I searched for "Alice Band" and found a definition in the 11th edition of The Chambers Dictionary:

Alice band n a wide hairband of coloured ribbon or other material (as worn by Alice in Tenniel's illustrations to Through the Looking-glass).

As a final aside, I looked up the published English translation of the above sentences - it's "Mitsuha wraps the cord around her head vertically, like a headband, and ties it into a bow over her left ear."