閉口

1. Origins, structure, and basic meaning

• Structure: The spelling is 閉口, read へいこう, and it combines 閉, meaning close, with 口, meaning mouth; it is used as a noun or with する.
• Basic usage: The basic sense of 閉口 is being fed up or at a loss because a situation is difficult to tolerate or handle.

2. Common pitfalls and similar expressions

• Exasperation rather than literal silence
  • The forms are 閉口している and 閉口した. They express exasperation or helplessness caused by an unpleasant situation or person, rather than simply closing one's mouth.
• Weariness with heat and boasting
  • 連日の暑さには住民もすっかり閉口している。 — Residents are completely fed up with the daily heat.
  • 彼の終わらない自慢話に皆が閉口した。 — Everyone was weary of his endless boasting.