Have you ever wondered why an ex is called an ex? I mean, at first I thought it would be short form to something longer like ex-tinct love or lover or ex-terminator like one who got rid of himself or herself as a pest from your life. Or even ex-travagant. One who spent so much of your time or money. But it’s not a short form for anything. It’s just an incomplete word, exactly like the incomplete relationship you had with that person. It just is. Or was. EX.
To read further, here is the link,