Lent is a most unusual word. Germans call the forty day period between Ash Wednesday and Palm Sunday by the perfectly reasonable name Fastenzeit: the time for fasting. The French, mishearing the Latin quadrigesima, fortieth, call it Careme; whether they hear it as having anything to do with quarant, forty, well, je ne sais pas. The Italian quaresima (Italians do indeed pronounce qu just as we do) is closer to their quarante, forty, so maybe they get the connection.
But the English Lent has nothing to do with forty. It is our old word for springtime: when the days lengthen. Thus it is related to words from both the Germanic and the Romance stock: English long , German lang , Latin
longus . Well thenwhy isnt it Longth or Lont ? How did that e get in there?
And the answer is umlaut. Thats what happen when a vowel (German, Laut ) turns around (German, um ), often by the influence of a vowel in the next syllable. Its common enough. Think of the vowel in the words cat, hat, mat. Say those words. Now use the same vowelsay it aloudfor carry, Harry, marry. Tricky, aint it? The vowel in cat is low: its pronounced with the tongue low in the mouth. But the vowel y at the end of carry is high and up front: its pronounced with the tongue near the roof of the mouth. So we anticipate the second vowel by raising the first, and instead of saying carry, Harry, marry, we say Kerry, hairy, Mary. At least, a lot of English speakers do: for them, Larry rhymes with dairy.
Some Anglo Saxon adjectives turned into nouns by the addition of a suffix: ith. That eety-beety vowel in that suffix, that leetle i, changed the previous vowel. It moved the o of long up front and made it e. Then, after it had done its dirty work, it slipped away. So we have the adjective long, but the noun length; the adjective broad, but the noun breadth; the adjective strong, but the noun strength. It couldnt do a job on the adjective wide, because the vowel was already high and up front (originally pronounced weed ): wide, width. Avast, villain!