Robertson Davies, one of my favourite authors, has a great bit in one of his books along those same lines...

One uneducated character is claiming that he is actually related to a recently deceased guy, and therefore has claims on his estate, because when his mother was alive she had an affair with this guy, and had the only "organism" of her life - therefore somehow confirming that he was conceived at that moment. The other (real) relatives of the dead guy, when discussing this situation, keep jokingly referring to "organisms" instead of "orgasms" and they realize that they are beginning to use the new word instead! (Now any time I see the word "organism" I smile to myself...)