- The definition of alas is to express unhappiness, sorrow or regret.
An example of alas is someone saying they wish they'd known about an event before rsvp'ing for another, such as "Alas, I wish I would have known about the event because I have already agreed to go somewhere else."
alas definition by Webster's New World
Origin: Middle English ; from Old French a las, helas ; from a-, he-, ah plush las, wretched ; from Classical Latin lassus, weary
alas definition by American Heritage Dictionary
Origin: Middle English, from Old French a las, helas, ah (I am) miserable, from Latin lassus, weary; see lē- in Indo-European roots.