Foggiest

[fog-ee, faw-gee] /ˈfɒg i, ˈfɔ gi/

adjective, foggier, foggiest.
1.
thick with or having much ; misty:
a foggy valley; a foggy spring day.
2.
covered or enveloped as if with :
a foggy mirror.
3.
blurred or obscured as if by ; not clear; vague:
I haven’t the foggiest notion of where she went.
4.
bewildered; perplexed.
5.
Photography. affected by .
/ˈfɒɡɪ/
adjective -gier, -giest
1.
thick with fog
2.
obscure or confused
3.
another word for fogged
4.
not the foggiest, not the foggiest idea, not the foggiest notion, no idea whatsoever: I haven’t the foggiest
adj.

1540s, perhaps from a Scandinavian source, or formed from fog (n.1) + -y (2). Foggy Bottom “U.S. Department of State,” from the name of a marshy region of Washington, D.C., where many federal buildings are (also with a suggestion of political murkiness) popularized 1947 by James Reston in “New York Times,” but he said it had been used earlier by Edward Folliard of “The Washington Post.”