Japanese

Noun

葉層 ‎(hiragana ようそう, romaji yōsō, historical hiragana えふそう)

1. (geology) lamina (fine layer that occurs in sedimentary rocks)

References

1. ↑ 2006, 大辞林 (Daijirin), Third Edition (in Japanese), Tōkyō: Sanseidō, ISBN 4-385-13905-9