coffin
樿 centers on a wooden container for the dead: a coffin. The meaning is narrow and concrete, with no clear extended senses.
樿 combines 木 (tree/wood) with 單, which likely contributes the sound. The character is used for a wooden coffin, but the exact historical development is uncertain.
The left side 木 is wood, and the right side 單 looks like a simple box. Picture a plain wooden box used as a coffin.
For セン, imagine a solemn scene: a wooden coffin (樿) being carried in a quiet procession. The word 'scene' cues セン.