noun
Refers to the fruit or tree; the katakana form クエン is standard. The synonym シトロン is more common in everyday contexts.
See also: シトロン
クエンはマーマレードや砂糖漬けに使われることがある。
Citrons are sometimes used for marmalade or candied peel.
シトロン is the more common loanword for citron; クエン is a rarer, more technical or traditional term.
The reading くえん is derived from Chinese; the exact historical derivation is uncertain.