鼻水

1. Origins, structure, and basic meaning

• Structure: 鼻水 (はなみず) is a noun for nasal discharge or the mucus associated with a runny nose.
• Basic usage: It describes one's nose beginning to run in the cold or wiping one's nose before entering a warm room.
  • 寒い外を歩いていたら鼻水が出てきた。 — Walking outside in the cold made my nose begin to run.
  • 弟は鼻水を拭いてから温かい部屋に入った。 — My younger brother wiped his nose and entered the warm room.

2. Common pitfalls and similar expressions

• Coming out and wiping
  • 鼻水が出る uses が for the discharge that appears, while 鼻水を拭く uses を for what a person wipes away.