Parallelepipedon

[Johnny_L.A]

Amelia Earhart said:

@Amelia Earhart

[My father] could define the hardest words as well as the dictionary, and we used to try to trip him up and he to bewilder us. I still have a letter he wrote me beginning ‘Dear Parallelepipedon,’ which sent me scurrying for a definition.

Is there another definition of parallelepipedon than the usual one? Or was there some reason that A.E.'s father would call her a kind of prism? (Her features were somewhat angular.) Or is this a case of him just wanting to use a word A.E. didn’t know?