reed, rush
荻 centers on a tall, water-loving plant: a reed or rush, the kind that grows in marshes and along riverbanks.
荻 combines the grass radical 艹 with 狄, which likely provides the sound テキ. The character refers to a specific type of reed.
The grass top 艹 sits above 狄, which looks like a beast 犭 near fire 火. Picture a reed growing tall in a marshy field where wild animals hide near a campfire.
For テキ, imagine a reed swaying in the wind and making a soft 'teki-teki' sound as its stems tap together: teki -> テキ.