Meaning of the word "no more than the man in the moon" in English

What does "no more than the man in the moon" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

no more than the man in the moon

US /noʊ mɔːr ðæn ðə mæn ɪn ðə muːn/
UK /nəʊ mɔː ðæn ðə mæn ɪn ðə muːn/
"no more than the man in the moon" picture

Idiom

used to emphasize that someone knows absolutely nothing about a particular subject

Example:
He knows about nuclear physics no more than the man in the moon.
She understands my feelings no more than the man in the moon.