Archaic derogatory term for a foolish or slow-witted person; not used in modern standard Japanese.
江戸時代の文献に「温」という罵倒語が見られる。
The derogatory term 温 appears in Edo-period documents.
温 (ぬく, 'idiot') and 温い (ぬくい, 'warm') share the same kanji and root reading but are completely different words in meaning.
warmth
snugly; cosily; warm and comfortable · carefree; without hardship; living comfortably · freshly made and still warm · shamelessly; imprudently; brazenly
warm; mild; pleasantly hot
warmth
warm; mild; pleasantly hot
The historical derivation is uncertain; the kanji 温 (warm) is used here as ateji for a derogatory term, unrelated to its usual meaning.