Blur

flou

(Something that appears hazy or indistinct)

marque

(A smear, smudge or blot)

salissure

(A smear, smudge or blot)

tache

(A smear, smudge or blot)

brouiller

(make indistinct or hazy, to obscure or dim)

estomper

(make indistinct or hazy, to obscure or dim)

s'estomper

(become indistinct)