not have the faintest/foggiest

not have the foggiest (notion)

To have no knowledge or understanding about something. He doesn't have the foggiest notion how hard it is to run a business. A: "Do you know where the car keys are?" B: "I haven't the foggiest. Sorry."See also: foggy, have, not

not have the faintest (idea)

have no idea. informalSee also: faint, have, not

not have the foggiest (idea or notion)

have no idea at all. informal, chiefly BritishSee also: foggy, have, not

not have the ˈfaintest/ˈfoggiest (idea)

(British English, informal) have no idea at all about something; not know anything at all: I haven’t got the faintest idea what to buy Roger for his birthday. ♢ ‘Where are we?’ ‘I’m afraid I haven’t the foggiest.’See also: faint, foggy, have, not