How to say "knee" in Japanese

• 膝ひざJLPT N3approx.Common
  nounThe ordinary word for the knee as a body part, covering both the joint and the front of the leg. Use it in everyday contexts such as injuries, sitting, or resting hands on the knees.
  水みずは私のひざの高たかさだった。↗

  The water came up to my knees.
• ニーCommon
  nounA loanword rendering of 'knee'; it mainly appears in borrowed or technical expressions rather than as the everyday word for the body part, so 膝 is usually what you want.

For the body part, 膝 is the normal Japanese word; 「ニー」 is essentially the loanword form, mainly heard in specialized or borrowed expressions, so learners should default to 膝.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 膝ひざknee
• ニーknee
• 小膝こひざknee
• 膝部しつぶknee (region)