slander, ridicule, proceed slowly
姍 centers on negative speech and slow movement: slandering, ridiculing, or proceeding slowly. The meanings do not share one clear conceptual center; slander and ridicule are verbal attacks, while proceeding slowly is a separate idea of unhurried motion.
姍 combines 女 (woman) with 冊, but the historical role of 冊 is uncertain. It may have contributed sound, but the exact development is unclear.
A woman 女 beside a stack of writing tablets 冊: imagine her slowly reading through them and finding slanderous gossip to ridicule.
For サン, picture the woman slowly reading under the sun: sun -> サン, and her slow pace matches the unhurried meaning.