sake cup
盞 centers on a small vessel for drinking sake: a sake cup. The meaning is narrow and concrete, with no strong abstract extensions.
盞 combines 皿 (dish, vessel) with 戔, which likely contributes the sound and may relate to smallness or cutting, suggesting a small drinking vessel.
The bottom 皿 is a dish, and the top 戔 looks like two small spears 戈 guarding a tiny cup. Picture a small sake cup resting on a dish, protected by miniature spears.
For サン, imagine a sake cup sitting in the sun: sun -> サン, and the warm sun shines on the little cup.
marigold; Calendula officinalis