noun
left and right kanji radicals
Traditional term specifically for the left-side radical (偏) and right-side radical (旁) of a kanji. Used in discussions of character structure.
漢字の偏旁を覚えると、部首の理解が深まる。
Learning the left and right radicals of kanji deepens your understanding of bushu.
noun
kanji radical positions
Colloquial extension that now covers all radical positions (冠, 脚, 構, 垂, 繞, etc.), not just left and right. Often used loosely in everyday talk about kanji components.
「偏旁」って言葉、今は冠とか脚も含めて使うよね。
The word 'henbou' is now used to include crown and foot radicals too, right?
部首 refers to the official classifier radical of a kanji, while 偏旁 refers to the positional components (left/right or, colloquially, any position).
Compound of 偏 (left-side radical) and 旁 (right-side radical). The extended colloquial sense arose from using the term loosely for all radical positions.