Scarecrow
wiktionary
From scare + crow. Replaced original shewel from Middle English sheweles, of unclear origin but probably from an unattested Old English form, composed of scȳn + -els (Old English scīewels). Compare Middle Low German schūwelse and Middle High German schiusel. See further at shy. Another replaced term for the thing was shoy-hoy, perhaps imitative of the cry of crows, in addition to bogle.
etymonline
scarecrow (n.)
1550s, from scare (v.) + crow (n.). Earliest reference is to a person employed to scare birds. Meaning "device of straw and cloth in grotesque resemblance of a man, set up in a grain field or garden to frighten crows," is implied by 1580s; hence "gaunt, ridiculous person" (1590s). An older name for such a thing was shewel. Shoy-hoy apparently is another old word for a straw-stuffed scarecrow (Cobbett began using it as a political insult in 1819 and others picked it up; OED defines it as "one who scares away birds from a sown field," and says it is imitative of their cry). Also fray-boggard (1530s).
