Readings & Meanings:
thin, light, weak, pale
I didn't prepare enough, so when the time came, I felt like I was skating on thin ice.
When doing calligraphy, you draw your characters with brush and ink on a thin piece of paper called "honshi".
Around 60 my hair slowly became thinner and thinner.
The grass crown (艸, くさかんむり) is on top of 溥 (meaning widespread).
Let's take 溥 apart.
寸 is on the bottom. We've seen this in 時. It's a hand exerting pressure. Think of it as a measuring idea.
甫 is above 寸. 甫 comes from a picture of a seedling sprouting from a rice field. The idea is that seedlings spread through fields, so 甫 means broad, wide.
Finally, we've got 水 on the right in the San-zui form, the three drops.
Put it together: when you measure water that is widespread, you'll find it is SHALLOW.
Grass, living in shallow water, is bound to be THIN.
厚, thick. My post on 厚 is here: http://sokasoka.blogspot.com/2008/02/thick-warm-gentle-rude-make-up-your.html