西南|せいなんseinan[0]heiban (flat)

1. nounsouth-west

• Synonym南西なんせいNeutralSame meaning — the direction between south and west. Preferred in weather and geography (「南西諸島」), and the more common choice in everyday use.
• Related未申ひつじさるWrittenThe same word, also written 「坤」 for the eight-trigram direction; likewise means southwest, now seen mostly in feng shui and writing on traditional directions.
• Antonym東北とうほくNeutralThe opposite direction, northeast; also the name of the Tōhoku region of northern Honshu. Directionally the reverse of 「西南」.

Use 「西南」 for the direction between west and south, as in 「西南の方角」, and in proper nouns like 「西南戦争」. For weather and geography 「南西」 is the usual word (「南西諸島」); 「未申」 is old-fashioned; the opposite direction is 「東北」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 南みなみと西にしの中間ちゅうかんの方位ほうい。