The Etymology of Length
Length belongs to a small, ancient club: English words formed by adding -th to an adjective to create an abstract noun.βββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ Long becomes length. Wide becomes width. Broad becomes breadth. Strong becomes strength. Deep becomes depth. This pattern descends from Proto-Germanic and was once a living part of the language, but it fossilised centuries ago. No new members have joined the club in modern English. The word itself traces from Old English lengΓΎu, built on lang ('long'), which came from Proto-Germanic *langaz and ultimately from PIE *dlonghos. That initial dl- cluster was simplified differently across language families β Latin produced longus (dropping the d-), while Germanic languages dropped the d- and kept the l-. The result is that English long and Latin longus are cousins, not parent and child, which is why elongate (from Latin) coexists with lengthen (from Germanic) with slightly different nuances. Length has remained remarkably stable across a thousand years of English. The spelling shifted from lengΓΎu to lengthe to length, but the pronunciation has barely moved. It serves as a quiet reminder that English's deepest vocabulary layer β the words for basic physical properties β tends to be Germanic rather than Latin, and tends to resist change more stubbornly than almost any other part of the lexicon.