Wordwind found my post on the chiasmus site needlessly obscure, and asked for an explanation by pm. She thinks my reply might be of general interest and suggested I post it to the board. Here it is:

Sorry, I didn't mean to be obscure. Chiasmi is fine. The problem is the parallel with octopus. Chiasmos is a Greek 2nd declension noun, plural chiasmoi, Latinised and Anglicised as chiasmi. Fine. No problem. Unfortunately pous (foot -- the final element of octopus) is a 3rd declension noun. The plural is podes (think of all the pod words with foot meanings). So if one wants to use the Greek plural it would have to be octopodes. Better by far to treat it as an ordinary English noun -- octopuses.

Bingley

Bingley