downscale (v.)

"in a descending direction, from a higher to a lower place, degree, or condition," late Old English shortened form of Old English ofdune "downwards," originally of dune "off from (the) hill," from dune "from the hill," dative of dun "hill" (see down (n.2)). The "hill" word is general in Germanic, but this sense development is peculiar to English. As a preposition, "in a descending direction upon or along,"  from late 14c.

To be down on "express disapproval of" is by 1851. Down home is from 1828 as "in one's home region," as an adjective phrase meaning "unpretentious" by 1931, American English. Down the hatch as a toast is from 1931. Down to the wire is 1901, from horse-racing.

Down Under "Australia and New Zealand" attested from 1886; Down East "Maine" is from 1825; Down South "in the Southern states of the U.S." is attested by 1834. Down the road "in the future" is by 1964, U.S. colloquial. Down-to-earth "everyday, ordinary, realistic" is by 1932.

[one of the skin plates on fish or snakes] c. 1300, from Old French escale "cup, scale, shell pod, husk" (12c., Modern French écale), from Frankish *skala or some other Germanic source, from Proto-Germanic *skæla "to split, divide" (source also of Dutch schaal "a scale, husk," Old High German scala "shell," Gothic skalja "tile," Old English scealu "shell, husk"), from PIE root *skel- (1) "to cut." A prehistoric cognate of scale (n.2) "weighing instrument."

In reference to humans, as a condition of certain skin diseases, it is attested from late 14c. Extended in botany to coverings of leaf-buds, etc., by 1776. As what falls from one's eye when blindness ends (usually figurative), it echoes Acts ix:18 (Latin tanquam squamæ, Greek hosei lepides).