Water level : The level formed by the surface of still water.

Water level : A kind of leveling instrument. See under Level, n.

Example:


Taxonomy
tube, water level, reservoir, transit, measurement, meniscus, hose, markings, copper tube, ID tube, laser level, lake, a level, the line, mop bucket, reservoir water levels, jim, spirit level.

Defination from the web:
water level why not just take 20' of 3/8" ID (Inside Diameter) clear tubing, and attach it to a coffee can with a soldered on 3 ... You are at the most level point when, moving the tube up or down about 1/32 inch, you note the water going from flat to dimpling--the ...