This is the 5600th most frequent Japanese word.
こし
"こし" (koshi) means "lower back" or "waist" in English.
Refers to the waist or lower back area.
彼は腰を痛めた。
He injured his lower back.
Refers to the act of bending at the waist.
腰を低くすることで通り抜けた。
He passed through by lowering his waist.
Used metaphorically to imply a steady and determined approach.