Right-side knife radical, the upright two-stroke form of 刀. Carries the cutting meaning - 剔 is to scrape flesh from bone, pick teeth, or weed something out, all sharp-edged operations. Places 剔 in the blade family with 切, 割, 剪, 利.
Left side 易 supplies the sound - yì shifting to tī through an i-vowel reading preserved in old rimes. 易 originally pictured a lizard with shifting skin colours, lending a faint sense of changing or working something away. Same phonetic appears in 踢 (to kick) and 惕 (alert).
