Proto-Indo-European root meaning "beyond."
It forms all or part of: adulteration; adultery;
alias; alibi; alien; alienate; alienation;
allo-; allopathy; allotropy;
alter; altercation; alternate; alternative; altruism; eldritch; else; hidalgo;
inter alia; other; outrage; outrageous; outre;
ulterior; ultimate; ultra-.
It is the hypothetical source of/evidence for its existence is provided by:
Sanskrit anya "other, different," arana- "foreign;"
Armenian ail "another;"
Greek allos "other, different, strange;"
Latin alius "another, other, different," alter "the other (of two)," ultra "beyond, on the other side;"
Gothic aljis "other,"
Old English elles "otherwise, else,"
German ander "other."