笑

Top bamboo-radical ⺮ (the side/top form of 竹) - the indexing radical. Etymologically a phonetic loan: ancient writers grafted bamboo above 夭 because of sound, but a folk reading became canonical - a bamboo bending in the wind looks like someone laughing, head tipped back. Pulls 笑 in alongside 笔 (brush), 篇 (chapter).

Bottom 夭 - historically the phonetic in 笑 (yāo → xiào shows drift, but 笑 had multiple readings in old texts). 夭 pictures a person with head bent over. The bent-figure imagery fuses with the bamboo above: someone doubled over laughing. Mnemonic favourite - bamboo-bowing-with-laughter.