JLPT1 G7 S15 F2073
As per 保# (cover) + 衣 clothing → large/loose-fitting robe or other clothes that cover the body → large. *Praise*, *commend* and *reward* are borrowed meanings. Compare and contrast 褓, which too is composed of 保 + 衣 (the latter in the form 衤).
[Full Kanji Etymology List]