Correct spelling for the English word "more retardo" is [mˈɔː ɹɪtˈɑːdə͡ʊ], [mˈɔː ɹɪtˈɑːdəʊ], [m_ˈɔː ɹ_ɪ_t_ˈɑː_d_əʊ] (IPA phonetic alphabet).
The phrase "more retardo" does not have a known etymology because it is not a recognized or commonly used term in any language. "More" means "greater in amount, number, or size" in English, and "retardo" is not a recognized word in any language. It may be a combination of English and Spanish, but it does not have an established origin or meaning.