Synonyms for Befog:

adj.

obscure (adjective)
shade.

n.

befog (noun)
cloud, fog, becloud, haze over, obscure, mist.

v.

blur (verb)
dim, obscure, blear, shade, becloud.
camouflage (verb)
obfuscate.
cloud (verb)
fog, gloom, eclipse, mist, shadow, overshadow.
dim (verb)
cloud, dull.

Other synonyms:

eclipse, obfuscate, overshadow, blear. Other relevant words:
dull, cloud, overshadow, dim, shadow, eclipse, shade, gloom, blear, obfuscate.