虚弱

1. Origins, structure, and basic meaning

• Structure: 虚弱(きょじゃく) is a noun and な-adjective for physical frailty or weakness.
• Basic usage: It ends a statement as 体が虚弱だ and modifies a noun as 虚弱な体.

2. Common pitfalls and similar expressions

• Linking form
  • Use だ when 虚弱 completes a statement and な when it directly modifies a following noun.
• Type of weakness
  • It suits a physically frail condition or constitution rather than merely being tired for a short time.