Source : Webster's Revised Unabridged Dictionary (1913)

Frugally \Fru"gal*ly\, adv.
   Thriftily; prudently.

Source : WordNet®

frugally
     adv : in a frugal manner; "in villages, the new pipeline marks the
           end of water as a precious liquid, to be dispensed
           frugally, weighed out drop by drop"