南海|なんかいnankai[0]heiban (flat)

1. nounsouthern sea

• Related南洋なんようWrittenWritten/formal prose. Refers to the Pacific around the equator, or the South Sea islands as known before WWII; 「南海」 is the general term for any southern sea.
• Antonym北海ほっかいNeutralNeutral. Means a northern sea, or the North Sea of Europe; the opposite of 「南海」 in the north-south sense.

Use 「南海」 for a southern sea in general, as in 「南海トラフ」. For the Pacific around the equator, or the prewar South Sea islands, use the written word 「南洋」; its opposite is 「北海」.

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

1. 南みなみの方ほうの海うみ。