Sure, I’m happy to help explain the abbreviation ‘ETAL’! “Et al.” is an abbreviation for the Latin phrase “et alii” which means “and others.” It is used in academic papers, research articles, and bibliographies to indicate that there are additional authors or contributors beyond the ones listed. In the context of a crossword puzzle, the clue “Abbr. at the end of a series” likely refers to the use of “et al.” at the end of a list of names, such as when citing sources or naming collaborators on a project. The abbreviation ‘ETAL’ is commonly used in crossword puzzles to represent these final “and others” in an abbreviated manner. So, if you ever come across a crossword clue asking for an abbreviation at the end of a series, remember that ‘ETAL’ is the likely answer, indicating that there are additional people or sources involved beyond those listed.