"spiked metal ring for holding a belt, etc.," c. 1300, bukel, from Old French bocle "boss (of a shield)," then "shield," then by further extension "buckle, metal ring," (12c., Modern French boucle), from Latin buccula "cheek strap of a helmet," in Late Latin "boss of a shield," diminutive of bucca "cheek" (see bouche).
Boucle in the middle ages had the double sense of a "shield's boss" and "a ring"; the last sense has alone survived, and it metaph. developed in the boucle de cheveux, ringlets. [Kitchin]
"star of David," six-pointed star, symbol of Judaism or Zionism, 1904, from Hebrew maghen Dawidh "shield of David," king of Judah and Israel, who died c. 973 B.C.E.
old Italian silver coin current 17c.-19c., 1640s, Italian, literally "shield" (in reference to the device it bore), from Latin scutum "a shield," in Medieval Latin "a coin" (see escutcheon). Also compare Anglo-French scute, variant of Old French escu (see ecu) and Middle English scute "French gold coin worth about half an English noble," c. 1400, from Medieval Latin.
If so, the original notion is of a compact body of men protected by interlocking shields. OED finds this "untenable" and proposed derivation from shield + -ture. Figurative sense is recorded from 1580s; meaning "temporary lodging for homeless poor" is first recorded 1890 in Salvation Army jargon; sense of "temporary home for animals" is from 1971. Related: Shelterless.
