月と鼈

Japanese

Kanji in this term
月	鼈
つき Grade: 1	すっぽん Hyōgaiji
kun’yomi

Alternative spellings
月とすっぽん月に鼈月にすっぽん

Etymology

Phrase consisting of 月 (tsuki, “moon”) +‎ と (to, “and”, conjunctive particle) +‎ 鼈 (suppon, “Chinese soft-shell turtle”), expressing the sense “(the difference between) the moon and a turtle”.[1][2][3]

Perhaps simultaneously evoking their similar shape but different locations (the sky vs. the ground), in the same manner as 雲泥の差 (undei no sa, literally “difference between the clouds and mud”).

First attested in 1734.[1]

Pronunciation

IPA^(key): [t͡sɨᵝkʲi to̞ sɨ̥ᵝp̚põ̞ɴ]

Noun

月(つき)と鼈(すっぽん) • (tsuki to suppon)

[from 1734] (idiomatic) night and day, completely different
Synonyms: 雲泥の差 (undei no sa), 雲泥万里 (undei manri), 提灯に釣り鐘 (chōchin ni tsurigane)

Usage notes

Also encountered using the particle に (ni) instead of と (to).

References

“月と鼈”, in 日本国語大辞典 (Nihon Kokugo Daijiten, “Nihon Kokugo Daijiten”)‎ (in Japanese), 2nd edition, Tōkyō: Shogakukan, 2000, →ISBN
“月と鼈”, in デジタル大辞泉 (Dejitaru Daijisen)‎ (in Japanese), Tōkyō: Shogakukan, updated roughly every four months
2006, 大辞林 (Daijirin), Third Edition (in Japanese), Tōkyō: Sanseidō, →ISBN

[KDJ2-1] “月と鼈”, in 日本国語大辞典 (Nihon Kokugo Daijiten, “Nihon Kokugo Daijiten”)‎ (in Japanese), 2nd edition, Tōkyō: Shogakukan, 2000, →ISBN

[DDJS-2] “月と鼈”, in デジタル大辞泉 (Dejitaru Daijisen)‎ (in Japanese), Tōkyō: Shogakukan, updated roughly every four months

[DJR-3] 2006, 大辞林 (Daijirin), Third Edition (in Japanese), Tōkyō: Sanseidō, →ISBN