noun
skirt (of a kimono); hem (of a kimono)
Refers specifically to the lower part or hem of a traditional kimono. Not used for Western-style skirts.
着物の褄が少しほつれている。
The hem of the kimono is slightly frayed.
彼女は歩くとき、褄を気にしていた。
She was mindful of the skirt of her kimono as she walked.
裾 is a more general word for the hem or lower part of any garment, including Western clothes, while 褄 is specific to kimono.
着物 is the garment itself; 褄 is a part of it.
The kanji 褄 is composed of 衣 (clothing) and 妻 (wife), but the historical derivation is uncertain. The reading つま is native Japanese.