Source : Webster's Revised Unabridged Dictionary (1913)

Preciously \Pre"cious*ly\, adv.
   In a precious manner; expensively; extremely; dearly. Also
   used ironically.

Source : WordNet®

preciously
     adv 1: in a precious manner; "his preciously valuable collection"
     2: extremely; "there is precious little time left" [syn: {precious}]