kanji 'brush' radical
Refers to the kanji radical ⺻ (⺻), known as the 'brush' radical, typically positioned on the right side of characters such as 筆 (brush) and 書 (write). Used in kanji classification and dictionary lookup.
The right-hand part of 筆 is called the 'brush' radical.
The name for 聿 when used as a right-hand component, formed from ふで, “brush,” and つくり, “right-hand component”; rendaku produces づくり.