"McChristian" is a surname with a unique spelling that can be explained using IPA phonetic transcription. It is spelled as /məkˈkrɪstʃən/ which indicates that the "Mc" prefix is pronounced as a separate syllable with a schwa sound followed by a hard "k" sound. The rest of the word follows a common spelling pattern for the surname "Christian". Despite the unusual spelling, the pronunciation of McChristian can be easily deciphered with the help of phonetic transcription.
There is no widely recognized or established etymology for the term "McChristian" because the word does not have a long history or widespread usage. It seems to be a coined term, combining the prefix "Mc-" often used in surnames to indicate "son of" or "belonging to", with the word "Christian", which refers to a believer or follower of Christianity. It may have been created as a play on words or used in certain contexts to mock or satirize certain perceptions or practices associated with Christianity. However, without a clear origin or widespread usage, it is difficult to determine a precise etymology for the term.