The kanji 筋 generally refers to something linear, strong, and often related to fibers or lines. This can be literal, like muscle fibers or veins, or figurative, representing a line of thought, a logical path, or even a sense of natural ability or aptitude. It implies a degree of inherent structure or characteristic.

・On-yomi (音読み): kin (キン) ・Kun-yomi (訓読み): 筋 (suji)

⚫︎ 筋肉（きんにく） Translation: muscle ⚫︎ 筋道（すじみち） Translation: logic; reason; method ⚫︎ 腕筋（うでじ） Translation: strength; ability; skill

The kanji 筋 is a pictograph. It depicts the lines or fibers of muscle. It shows how the structure of something strong and supportive is made up of smaller units. The shape visually represents the arrangement of these fibers and the strength associated with them. The radical is 月 (tsuki/getsu), meaning "moon" or "flesh," showing the kanji's relationship with body parts. It symbolizes the essence of "sinew" or "fiber" found in muscles.