kanji 'horn' radical at left
Refers to the kanji radical 角 (つの) when it appears on the left side of a character, as in 解 or 触.
The left part of the kanji 解 is called つのへん (the 'horn' radical at left).
Compound of 角 (つの, 'horn') and 偏 (へん, 'left-side radical').