Source : Webster's Revised Unabridged Dictionary (1913)

Tapster \Tap"ster\, n. [AS. t[ae]ppestre a female tapster. See
   {Tap} a plug, pipe, and {-ster}.]
   One whose business is to tap or draw ale or other liquor.

Source : WordNet®

tapster
     n : a tavern keeper who taps kegs or casks [syn: {tapper}]