墓穴

1. Origins, structure, and basic meaning

• Structure: Spelling: 墓穴. Reading: はかあな. Core meaning: grave pit; one's own trap.
• Basic usage: Representative examples: 作業員は墓石を置くための墓穴を慎重に掘った / 言い訳を重ねたせいで自分から墓穴を掘った.

2. Common pitfalls and similar expressions

• Reading difference between a literal pit and the idiom
  • A literal grave pit, 墓穴, is read as はかあな, while the idiom 墓穴を掘る is read as ぼけつをほる. The idiom means creating one's own disadvantage through excuses or actions, not performing a literal burial act.