Advertisement Upgrade to remove ads


the process by which water changes from liquid form to an atmospheric gas


the process by which water evaporates from a plant's leaves


the process by which molecules of water vapor in the air become liquid water


The falling to earth of any form of water (rain or snow or hail or sleet or mist)


the movement of surface water into rock or soil through cracks and pore spaces


The downward movement of water through soil and rock due to gravity.

surface run off

water flowing off the land into bodies of surface water (for example, lakes or rivers).

ground water

water found beneath Earth's surface in aquifers


the movement of water from soil into the roots of plants.

cloud formation

Water vapor condensing in the atmosphere around dust or ice particles

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording