Definition of fog:
(n) :
a new growth of
grass appearing on a field that has been
mowed or
grazed; tall and decaying
grass left standing after the cutting or grazing season
"he did so many drugs, he was still in a fog three months after going through detox."
(v) :
to become covered with or as if with fog; to become obscured in
condensation or
water
"the mirror fogged every time he showered."