• (n.) An instrument for measuring the height of water in a river; a river gauge.
Flu`vi·om'e·ter noun [ Latin fluvius river + -meter .] An instrument for measuring the height of water in a river; a river gauge. 
fluviometer An instrument for measuring the rise and fall of rivers. Related 'measure' and 'metric' words and charts: mens-; Metric Chart of Units; Metric-Length Converter; Metric Units and Links.