IPA: /ˈspɒt.ləs/
KK: /ˈspɑt.ləs/
Completely clean and without any marks or stains.
The kitchen was spotless after she finished cleaning it.
Comparative: more spotless
Superlative: most spotless
Spotless → It is formed from "spot" (from Old English *spon*, meaning a mark or stain) and "-less" (meaning without). The word "spotless" means without any marks or stains, completely clean.
Think of being 'without' ('-less') any 'marks' or 'stains' ('spot') — that's why spotless means completely clean.