spotlessly

From spotless + -ly.

spotlessly (comparative more spotlessly, superlative most spotlessly)

1. In a spotless manner.
   • 1955 April, Cecil J. Allen, “British Locomotive Practice and Performance”, in Railway Magazine, page 261:

     And the kaleidescope ^[sic] of distinctive colours sported by the spotlessly-maintained diesels of many different railways in the great Union stations of cities like Washington and St. Louis must have some thrills even for the most die-hard steam enthusiast.

• stoplessly