Why is the ninth month called September?
Old English þrescold, þærscwold, þerxold "doorsill, point of entering," first element related to Old English þrescan (see thresh), with its original sense of "tread, trample." Second element of unknown origin and much transformed in all the Germanic languages; in English it probably has been altered to conform to hold, but the oft-repeated story that the threshold was a barrier placed at the doorway to hold the chaff flooring in the room is mere folk etymology. Cognates include Old Norse þreskjoldr, Swedish tröskel, Old High German driscufli, German dialectal drischaufel.
threshold thresh·old (thrěsh'ōld', -hōld')
The place or point of beginning; the outset.
The lowest point at which a stimulus begins to produce a sensation.
The minimal stimulus that produces excitation of any structure, eliciting a motor response.
(1.) Heb. miphtan, probably a projecting beam at a higher point than the threshold proper (1 Sam. 5:4,5; Ezek. 9:3; 10:4,18; 46:2; 47:1); also rendered "door" and "door-post." (2.) 'Asuppim, pl. (Neh. 12:25), rendered correctly "storehouses" in the Revised Version. In 1 Chr. 26:15, 17 the Authorized Version retains the word as a proper name, while in the Revised Version it is translated "storehouses."