et al.
Et al., I was introduced to this beauty in 8th grade. This was when we were doing deed searches in a school project, and I learned not to abbreviate et, which means, of course, “and”. I was trying to remember what al. was an abbreviation for, so I googled it. There are no less than six words for which al. may be the abbreviation: alius (singular), alii, aliae, alia (masculine, feminine, neutral plural for others), alter (perhaps the infinitive?), alibi (for other references, it says).
No wonder it's abbreviated!