rob
簒 centers on taking something by force or stealth: robbing or usurping what belongs to another.
簒 is a variant form of 篡, which combines 厶 (private) with 算 (calculate) to suggest scheming or plotting to seize power. The exact historical development of the 簒 shape is uncertain.
The top 竹 suggests bamboo tools, and the middle 目 is an eye. Below, 大 (big) and 么 (small) hint at taking everything. Picture a thief using a bamboo pole to pry open a window, eyeing the room, and robbing both big and small valuables.
For サン, imagine a robber stealing sand from a beach: sand -> サン, and the thief scoops it up with a bamboo basket.