noun
moisture
MOYS-cher/ˈmɔɪstʃər/
A small amount of water or other liquid in or on something.
Tiny beads of moisture remain inside the sponge's open pores.

Etymology
Old French moistour named dampness or wetness as a condition. The selected English sense names the small amount of liquid responsible for that condition.
In context
this mulch layer this is gonna help retain moisture and keep the temperature more um so it doesn't fluctuate as fast
More examples
- Mulch helps the soil retain moisture.
- This lotion adds moisture to dry skin.
- Moisture collects on the bathroom mirror during a hot shower.
Forms
moist adjective — Slightly wet, especially on the surface.
moisturize verb — To add or restore moisture to skin.
Similar words
- dampness
- Emphasizes a slightly wet condition rather than liquid itself.
- humidity
- Refers specifically to water vapor present in the air.