The spelling of the word "Domeniga" may seem irregular when considering typical English spelling rules. However, it is important to note that this is actually the Italian version of the name "Sunday". In Italian, the letter "i" is often used as a plural form, explaining the addition of this letter. The pronunciation of "Domeniga" can be written in IPA as /doˈmɛniga/, with the stress on the second syllable.
There is not enough information available to determine the etymology of the word "Domeniga". Without any context or specific language reference, it is difficult to provide an accurate origin for this word.