土竜

 モグラ on Japanese Wikipedia

A surface analysis suggests a derivation from the verb 潜る (moguru, “to go underneath or into something, such as water or the ground”).

However, the modern mogura reading appears to be relatively recent. The older form of this noun was variously ugoromochi, uguromochi, or uguramochi, deriving from now-obsolete verb 墳つ (ugumotsu, uguromotsu, ugomotsu, ugoromotsu, “to become a pile or small hill, as of soil”). This verb itself appears to be a compound deriving from obsolete 穿ぐ (ugu, “to dig a hole”, a 下二段 (shimo nidan) or “lower bigrade” conjugation verb) + 持つ (motsu, “to have in hand; to carry, to bring”), with an underlying idea of “that which digs and brings up the dirt ”. The verb ugu had a 連体形 (rentaikei, “attributive form”) of uguru, attaching only to nouns, suggesting that the original parsing of this might have been “digging bringer”.

The shift in sound from uguru to the variants uguro and ugoro may be a reflection of the morpheme -ro that appears in numerous words indicating a hollow interior. Compare 空ろ (utsuro, “a hollow, an emptiness”), 室 (muro, “a room; an excavated dwelling on the side of a mountain”), 袋 (fukuro, “a bag”), possibly even 所 (tokoro, “a place”). The ugoromochi reading appears in the 本草和名 (Honzō Wamyō), a pharmacopoeia compiled some time in the years 901–923.

The uguramochi variant was either dialectal, or a later development.

With the beginning of the Edo period and the shift in the political and cultural center to Edo, uguramochi was superseded by the eastern dialectal form muguramochi. The 1603 日葡辞書 (Nippo Jisho, “Japanese-Portuguese Dictionary”) lists one variant as mugura, indicating that the mochi portion could be dropped. This mugura then became mogura, possibly influenced by the verb 潜る (moguru).

The kanji are jukujikun (熟字訓). See also Etymology 8.

• (Tokyo) もぐら (Heiban – )^[1]
• IPA^(key):

土竜(もぐら) or 土竜(モグラ) • (mogura) 

1. a mole (burrowing insectivore)

   Synonym: 田鼠 (denso)

• Given the irregularity of the kanji reading, the もぐら spelling may be more common for this word in general use.
• As with many terms that name organisms, this term is often spelled in katakana, especially in biological contexts (where katakana is customary), as モグラ.

• 金(キン)土竜(モグラ) (kinmogura, “golden mole”)
• 針(ハリ)土竜(モグラ) (harimogura, “echidna”)

Likely a shift in pronunciation from earlier eastern dialectal form muguramochi, possibly influenced by the verb 潜る (moguru).

• (Tokyo) もぐらもち (Nakadaka – )^[1]
• IPA^(key):

土竜(もぐらもち) • (moguramochi) 

1. a mole (burrowing insectivore)

• The もぐら reading further above is more common for this word.

Shortening of earlier eastern dialectal form muguramochi.

• IPA^(key):

土竜(むぐら) • (mugura) 

1. (rare, possibly obsolete) a mole (burrowing insectivore)

• The もぐら reading further above is more common for this word.

Eastern dialectal form of earlier uguramochi reading. Appears in the 日葡辞書 (Nippo Jisho, “Japanese-Portuguese Dictionary”) published in 1603.^[1]

• IPA^(key):

土竜(むぐらもち) • (muguramochi) 

1. (rare, possibly obsolete) a mole (burrowing insectivore)

Older western Japanese dialectal reading. Also appears with this reading in the 日葡辞書 (Nippo Jisho, “Japanese-Portuguese Dictionary”) published in 1603.^[1]

• IPA^(key):

土竜(うぐらもち) • (uguramochi) 

1. (rare, possibly obsolete) a mole (burrowing insectivore)

Variant of older western Japanese dialectal reading. Appears with this reading in the 玉葉和歌集 (Gyokuyō Wakashū, “Collection of Jeweled Leaves”) poetry compilation, completed in 1313–1314.^[2]

• IPA^(key):

土竜(うぐろもち) • (uguromochi) 

1. (rare, possibly obsolete) a mole (burrowing insectivore)

May be the oldest form. Appears with this reading in the 本草和名 (Honzō Wamyō), a pharmacopoeia compiled some time in the years 901–923.^[1]

Derived as the 連用形 (ren'yōkei, “continuative or stem form”) of verb 墳つ (ugumotsu, uguromotsu, ugomotsu, ugoromotsu, “to become a pile or small hill, as of soil”). See above for further details.

• IPA^(key):

土竜(うごろもち) • (ugoromochi) 

1. (obsolete) a mole (burrowing insectivore)
   • c. 918, 深根輔仁 [Fukane Sukehito], 本草和名 [Japanese Names of Herbs, Honzō Wamyō]:

     鼹鼠　楊玄操、音偃　一名隠鼠　一名鼢鼠　仁諝、音扶粉反　鼠王　大如水牛下脚、已上三名、出陶景注　鼢鼠　一名□鼠　音務　一名䥫鼠　已上二名、出兼名苑　和名宇古呂毛知

     (please add an English translation of this quotation)

From 土 (do, “earth”) +‎ 龍 (ryū, “dragon”). Perhaps used erroneously to refer to moles because they dwell underground just like earthworms. Compare Chinese 地龍／地龙 (dìlóng, “earthworm”, literally “earth dragon”), English earthworm, worm (“worm; dragon”), wyrm (“dragon; serpent”), Old English wyrm (“worm; serpent”).

• (Tokyo) どりゅう (Atamadaka – )^[1]
• (Tokyo) どりゅう (Heiban – )^[1]
• IPA^(key):

土(ど)竜(りゅう) • (doryū) 

1. (rare) a mole (burrowing insectivore)
2. (rare) an earthworm (worm (animal))

   Synonym: 蚯蚓 (mimizu)

3. (figurative) an outstanding horse; an excellent horse; a famous horse (by metaphor from the meaning of the kanji)

   Synonym: 竜馬 (ryūme)

• Fukane no Sukehito (c. 901–923) Maruyama Yumiko, Wu Qian, editors, Honzō Wamyō: Eiin, Honkoku to Kenkyū) (in Japanese), Kyūko Shoin, published 2021, →ISBN.
• Doi, Tadao (1603–1604) Hōyaku Nippo Jisho (in Japanese), Tōkyō: Iwanami Shoten, published 1980, →ISBN.