Agreed! But I assert that people would still recognize "a murder of crows" as such, even if they don't have a name for it - just like I would expect someone to

Agreed! But I assert that people would still recognize "a murder of crows" as such, even if they don't have a name for it - just like I would expect someone to be able to recognize an equilateral triangle as such, even if they don't know the name for it.