obfuscate : (v) render obscure, unclear, or unintelligible
The thick coating of dust obfuscated the detailed engraving, leaving only the impression of a silhouette recognizable.
Now here’s a word you can slip into conversation and come out the better for. Granted, you might not often get the opportunity to, but when it comes up—BAM. Whip it out and impress all your friends!
…Or make them stare at you blankly, whatever.