noun
round hole
A hole that is circular in shape. Used in everyday contexts, from woodworking to casual description.
板に丸穴をあける。
Drill a round hole in the board.
この部品には丸穴が三つある。
This part has three round holes.
角穴 means a square or rectangular hole, contrasting with the circular shape of 丸穴.
Compound of 丸 (まる, 'round') and 穴 (あな, 'hole'). The reading is straightforward kun'yomi.