also: ひょうちゅう
noun
icicle
The common word for an icicle, a hanging spike of ice formed by dripping water that freezes.
軒下に長いつららが下がっている。
A long icicle is hanging from the eaves.
暖かくなってつららが落ち始めた。
It got warmer and icicles started falling.
noun
ice pillar (for cooling a room)
Only when written 氷柱 · Only with reading ひょうちゅう
A pillar-shaped block of ice used historically to cool a room. This sense is restricted to the reading ひょうちゅう and is rare in modern usage.
昔の家では、夏に氷柱を部屋に置いて涼をとった。
In old houses, people placed an ice pillar in the room to keep cool in summer.
noun
Only with reading つらら
Archaic meaning for つらら, simply 'ice'. Not used in modern Japanese; the standard word for ice is 氷 (こおり).
古語では「つらら」が単に氷を指すこともあった。
In old language, つらら could simply mean 'ice'.
Kanji spelling for つらら. Can also be read ひょうちゅう, but that reading is restricted to the ice pillar sense.
Reading ひょうちゅう is used only for the ice pillar sense (sense 2). Rare in modern Japanese.
Rare kanji spelling for つらら. The character 氷 alone usually means 'ice' and is read こおり.
The word つらら is of native Japanese origin. The kanji 氷柱 literally mean 'ice pillar', which matches the icicle meaning. The reading ひょうちゅう is the on'yomi of these characters.