As a Greek, I feel the need to protest the corruption of the word cleistophobia (kleisto = closed) into claustrophobia. Claus- sounds like the root of "to cry" (e.g. clausigelos = crying laughter), so a Greek reading claustrophobia thinks of people who are afraid of crying (though the proper rendering of a word composite with that meaning would be klauthmophobia).

Claustro- comes from Latin Claustrum, which shares the same root as the Greek word. Claustrophobia wasn’t a word in Latin or Greek though, it’s a modern hybrid.

According to the etymological dictionary:

>From Latin claustrum (“a shut-in place”), from claudō (“I shut, close; I imprison, confine”) + -phobia. First attested in the British Medical Journal

So it's not a corruption. It's a neologism.

This might be a lost cause, as there really isn't a great word to use instead, and that usage is in modern dictionaries. Some alternative words are proposed here, but none of them really seem adequate: https://english.stackexchange.com/questions/281780/what-is-t...