セイ, セ, ソウ, よ, さんじゅう, とし, ゆ, ゆき
generation, world, society, public
JLPT4 G3 S5 F135
The relevant seal inscription form shows the top half of 枼 as described in 葉 (thin, flat leaves piled upon each other), suggesting successive generations figuratively piled one atop the other → *one generation* → *era* → *successive*; *for generations*; *life*; *the world* (← successive generations that make up life/the world; compare 葉 as well as 祖).
[Full Kanji Etymology List]