сморозить глупость означает в английский

put one's foot in one's mouth▼(say or do something embarrassing or wrong)
verb
[UK: ˈpʊt wʌnz fʊt ɪn wʌnz maʊθ] [US: ˈpʊt wʌnz ˈfʊt ɪn wʌnz ˈmaʊθ]