cutting
剔 centers on cutting in a precise, often removing or carving way. The idea is to cut something out or away, like gouging or shaving material off.
剔 combines 易 (likely phonetic, suggesting the sound) with 刂 (knife), indicating cutting or carving with a blade. The exact historical development of the phonetic component is uncertain.
The left side 易 looks like a sun 日 over something being pulled apart, and the right side 刂 is a knife. Imagine using a knife to cut away the top part, like carving out a shape.
For テキ, picture a cutting technique where you use a sharp blade: technique -> テキ, and the knife 刂 carves precisely.