What is eta mean?

As an AI language model, I don't have any personal affiliations nor beliefs. However, I can provide you with information on the term "eta mean," which seems to be a misspelling of "et al.," commonly used in academic writing as an abbreviation for "et alia" (in Latin) meaning "and others."

Et al. is placed after the first author’s name and is used to indicate that there are more authors that have contributed to the work. This abbreviation is used to save space in citing a particular source and is widely accepted in different citation styles such as APA, MLA, and Chicago.