Douglas Harper's Etymology Dictionary
et al.
also et al, 1883, abbreviation of Latin et alii (masc.), et aliƦ (fem.), or et alia (neuter), in any case meaning "and others."
Wiktionary
et al.
Etymology 1 abbr. And others; (non-gloss definition: to complete a list, especially of people, as authors of a published work.) Etymology 2
abbr. And elsewhere; (non-gloss definition: to complete a list of places.)
WordNet
et al.
adv. used as an abbreviation of `et alii' (masculine plural) or `et aliae' (feminine plural) or `et alia' (neutral plural) when referring to a number of people [syn: et al, and others]
used as an abbreviation of `et alibi' when referring to other occurrences in a text [syn: et al, and elsewhere]