radical in Chinese characters (Kangxi radical 13), occurring in 用[yong4], 同[tong2], 網|网[wang3] etc, referred to as 同字框[tong2 zi4 kuang4]
冂
=
丨
+
㇆
:
Mnemonic symbol from the shape of the character: kind of looks like a map.
Zeus (ju) found a secret map (冂) that tells the location of a golden dinosaur bone (丨) in front of the engine ((e)ng1), so he took a plow (㇆) and dug up everything. He actually found a couple of dinosaur bones, but not a golden one.