faultlessly

Adverb

faultlessly (comparative more faultlessly, superlative most faultlessly)

1. In a faultless manner.
   • The interior of the "castle" was as faultlessly neat as its exterior was novel. The entire space, some twenty feet by forty, was subdivided into several small sleeping-rooms; the apartment into which he first entered, serving equally for the ordinary uses of its inmates, and for a kitchen.1841, J[ames] Fenimore Cooper, The Deerslayer: A Tale. […], 1st British edition, volume (please specify |volume=I, II, or III), London: Richard Bentley, […], →OCLC
   • It is much easier to detect a fault than to produce a harmonious arrangement. And it is much easier for a man to see faults in a lady’s dress than to give directions for dressing faultlessly.1849, Timothy Shay Arthur, Advice to Young Ladies

   Synonyms:

   unfailingly, immaculately, impeccably