闪 has surprisingly varied uses: 闪开 (dodge/get away), 闪电 (lightning), 闪光 (flash), 闪腰 (pull a muscle in the back). The core idea is a sudden, quick movement.
culture
闪婚 (shǎnhūn, flash marriage) and 闪离 (shǎnlí, flash divorce) are modern slang for marrying or divorcing very quickly.
