not know one's arse from one's elbow
idiom
British, informal + impolite
: to know nothing : to be stupid
Don't take his word for it—he doesn't know his arse from his elbow.
Dictionary Entries Near not know one's arse from one's elbow
not know one's arse from one's elbow
Cite this Entry
“Not know one's arse from one's elbow.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/not%20know%20one%27s%20arse%20from%20one%27s%20elbow. Accessed 30 Nov. 2024.
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Merriam-Webster unabridged
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