It’s not in very common use nowadays, but at one time it was pretty common to see or hear phrases like “he’ll be at the race track on Thursday, as is his wont.” That doesn’t mean he “wants” to visit the race track. Even though obviously he does want to, “wont” and “want” are completely different words with virtually the same pronunciation.
“Wont” comes from the Old English word “gewunian,” which meant to stay in place. If you trace its roots back further, you find that it’s related to words meaning contentment and happiness, and that it shares its family tree with “win” and “wish.” “Wont” means habit or custom, so if his wont is to be “…at the race track Thursday,” that just means he customarily goes every Thursday. You could call this a “wont” whether he’s there for fun or because he has a part-time job cleaning up after the horses, in which case he probably doesn’t really “want” to be there at all.
“Want,” on the other hand, is a newer addition to English, arriving in the 1200s from the Old Norse word “vanta” (to be lacking). Originally “want” in English also meant “lacking,” and that sense is still around in phrases like “your solution to that problem was found wanting.” “Want” in this sense is almost the same as “need.” The phrase “did not want for” is still used to show that something is actually readily available as Charles Dickens used it in Oliver Twist in 1838:
“Mrs. Bumble did not want for spirit…”
In the 1700s “want” began to be used to mean something more like “desire,” which is its primary meaning nowadays. But in the 1800s the two senses of the word were in at least equal usage; Dickens, again, shows that both were in play:
“If every one of your clients is to force us to keep a clerk, whether we want to or not…”
Since we’re considering different version of “w-[a or o]-n-t”, we might as well also check “won’t.” “Won’t” is a contraction of “will not,” and completely unrelated to both “wont” and “want.” It seems like “won’t” really ought to be “willn’t” — and in fact it was! As recently as the 1800s it was common to hear or read things like this:
“That willn’t wash, Miss” (Charlotte Bronte wrote that in 1849).
However, “won’t” was also available at the time; “won’t” and “willn’t” coexisted from about the 1500s until the late 1800s when “willn’t,” for no particular reason, disappeared from use. “Won’t” comes from the Middle English “wynnot” or “wonnot”, and “won’t” is, strictly speaking not a contraction of “will not,” but a contraction of the Middle English “wonnot.” I don’t think it’s the wont of modern English speakers to favor a Middle English contraction over the equivalent modern English version, but apparently enough people wanted it that way for it to happen.
