Translation guide
Long johns are thermal underwear, typically covering the full legs and often with long sleeves, worn under clothes for warmth. In Japanese, the most common term is ババシャツ for tops and 股引 (ももひき) for bottoms, though modern thermal wear is often called 保温下着 or 防寒下着.
Thermal underwear is essential in winter.
Literally 'cold-protection underwear'. Emphasizes protection against cold.
I bought thermal underwear because I'm going skiing.
Colloquial term for a thermal undershirt, often associated with older styles or women's wear. Can sound slightly old-fashioned or humorous.
It's cold, so I'm wearing a thermal undershirt.
Specifically referring to the bottom part of long johns, like long underpants or leggings worn under trousers.
Traditional Japanese long underpants, often worn by men. Now also used for modern thermal leggings.
My grandfather wears long underpants in winter.
Kansai dialect term for long underpants, similar to 股引. Common in casual speech in western Japan.
Tights or leggings, often worn as thermal underwear by both men and women. Can refer to sports tights or fashion tights.
Leggings, often used as thermal innerwear. More associated with women's fashion, but also used for warmth.
Specifically the top part of long johns, a long-sleeved undershirt for warmth.
Literally 'long-sleeved underwear'. A straightforward, neutral term.
Wearing a long-sleeved undershirt keeps you warm.
As above, but specifically for the top. Very common in casual conversation.
I can't get through winter without a thermal undershirt.
Brand name (Uniqlo's HEATTECH) often used generically for thin, warm innerwear tops. Very common in modern Japanese.
Referring to a matching set of thermal underwear, both top and bottom.
The English term 'long johns' does not have a direct, single-word equivalent in Japanese. Using ロングジョンズ would not be understood. Instead, use the specific terms for top or bottom, or general terms like 保温下着.
While 股引 and ババシャツ are traditional and widely understood, younger generations may prefer ヒートテック (brand name) or 保温下着 for modern, thin thermal wear. ババシャツ can sound humorous or old-lady-ish.
寒いからパッチはいてるわ。
It's cold, so I'm wearing long johns.
スキーウェアの下にタイツを履く。
I wear tights under my ski wear.
冬はレギンスを重ね履きする。
In winter, I layer leggings.
It's cold today, so I wore my HEATTECH.
My grandma sent me thermal underwear (top and bottom).