1The moisture or liquid content contained in something (the body, food, air, etc.); commonly used when talking about hydration, dryness, or how juicy something is.
夏は汗をかくので、水分をこまめにとることが大切だ。
In summer you sweat a lot, so it's important to drink water frequently.
このスイカは水分が多くてとても甘い。
This watermelon is very juicy and sweet.
肌の水分が足りないと、乾燥してかゆくなる。
If your skin lacks moisture, it becomes dry and itchy.
洗濯物の水分をしっかり切ってから干してください。
Please wring out the moisture from the laundry thoroughly before hanging it to dry.