The characteristic or quality of being foggy(noun)
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Use "fogginess" in a sentence
"The road back has been more arduous than he ever possibly imagined when he was scratched out of the lineup following a game against Tampa Bay on Jan. 5 after experiencing what he's since described as "fogginess.""
"The road back has been more arduous than he ever imagined when he was removed from the lineup after experiencing what he has described as "fogginess" following game against Tampa Bay on Jan. 5."
"It all changed on Jan. 6 when he was diagnosed with concussion-like symptoms that he later described as "fogginess.""