ell

Etymology 1

From Middle English elle, elne, from Old English eln (“the length of the forearm from the elbow to the tip of the middle finger; a unit of measure”), from Proto-Germanic *alinō, from Proto-Indo-European *Heh₃l-én-eh₂, from *Heh₃l- (“elbow, forearm”). Cognate with Dutch el (“ell”), German Low German Ell (“ell”), German Elle (“ell”), Swedish aln (“cubit; ell”), Icelandic alin (“cubit; ell”), Latin ulna (“forearm”).

noun

1. (historical) A measure of length. An English ell was 1¼ yards (45 inches or 114 cm), a Scottish ell was about 37 inches (94 cm), a Flemish ell was ¾ yard (27 inches or 69 cm), while certain European ells were less than 50 cm.
   At certain times in the ice-mountains of Switzerland there happen cracks which have shewn the great thickness of the ice, as some of these cracks have measured three or four hundred ells deep. 1791, Erasmus Darwin, The Economy of Vegetation, J. Johnson, page 51
   A homely proverb recognises the existence of a troublesome class of persons who, having an inch conceded them, will take an ell. 1841, Charles Dickens, chapter XXX, in Barnaby Rudge
   If he had imputed to them conditions it was all his own doing: it came from his inveterate habit of abysmal imputation, the snatching of the ell wherever the inch peeped out, without which where would have been the tolerability of life? 1910, Henry James, The Finer Grain

Etymology 2

From the name of the letter L.

noun

1. The name of the Latin-script letter L. (more commonly el)
   I have drunk en-ee-cee-tee-ay-ar from the ef-ell-oh-doubleyou-ee-ar-ess in his gee-ay-ar-dee-ee-en many a time. 2004, Will Rogers, The Stonking Steps, page 170
2. An extension usually at right angles to one end of a building.
   I could hear them snapping and tearing around, and then one managed to get on the roof by jumping from the low ell. 1931, H. P. Lovecraft, chapter 4, in The Whisperer in Darkness
3. Something that is L-shaped.