越鳥南枝に巣くい、胡馬北風に嘶く
(Ecchou nanshi ni sukui, koba hokufuu ni inanaku;
“The bird from Yue builds its nest in southern branches;
the horse from Hu neighs at the northern wind”)

Definition:

An expression of homesickness or nostalgia. A southern bird living in the north will (supposedly) build its nest in the southern branches of a tree; a horse from the northern steppes will recognize the northern winds and give voice; so too will a human respond to things that remind them of their hometown or childhood.

Breakdown:

This saying is composed of two parallel independent clauses. The first begins with proper noun 越 (Yue, Japanese Etsu), a state that existed in the southeast of what is now China, over 2300 years ago. This proper noun compounds with and modifies the noun 鳥 (here chou), “bird.” This compound noun is not followed by any particles, but acts as the subject of the clause. Next we find the location particle に (ni) marking a compound comprising direction noun 南 (here nan), “south,” and 枝 (here shi), “branch.” The verb performed in this location is 巣くう (sukuu), “to build a nest,” appearing in conjunctive form in order to attach to the latter half of the phrase.

Following the same pattern, the second clause begins with the proper noun 胡 (Hu, Japanese Ko), a generic term for people living to the north and northwest, including various Mongolian and Turkic peoples and the Xiongnu. Little wonder, then, that the noun compounded with and modified by 胡 is 馬 (here ba), “horse.” This time, the following compound noun comprises direction 北 (here hoku), “north” and noun 風 (fuu), “wind.” The final verb is 嘶く (inanaku), “to neigh,” in conclusive form, and this time I’m parsing the particle に (ni) as a sort of directional marker; the north wind is something that the horse neighs in response to. (One could also read it as a marker for time; “when the north wind [blows].”)

Notes:

This imagery comes to us from a poem in the Wen Xuan (in Japanese『文選』= Monzen), a Chinese literary anthology from the third decade of the 6th century CE; its origins in Chinese antiquity explain why so much of the phrase itself uses Chinese-style readings.

Note that the phrase may be shortened by dropping the bird and only using the horse part; it may be further compacted into either of a pair of four-character compounds: 越鳥南枝 (ecchou nanshi) or 胡馬北風 (koba hokufuu).

Example sentence:

「胡馬が北風に嘶くように、僕も実家を出てから故郷、いや、州ですら懐かしくなってきました」

(“Koba ga hokufuu ni inanaku you ni, boku mo jikka wo dete kara furusato, iya, shuu de sura natsukashiku natte kimashita.”)

[“Like the northern horse that neighs at northern winds, since leaving my parents’ home I too have started thinking fondly of my hometown – no, of the entire state.”]