Easton's Bible Dictionary
Used in defensive warfare, varying at different times and under different circumstances in size, form, and material (1 Samuel 17:7; 2 Samuel 1:21; 1 Kings 10:17; 1 Chronicles 12:8, 24, 34; Isaiah 22:6; Ezek. 39:9; Nahum 2:3).
Shields were usually "anointed" (Isaiah 21:5), in order to preserve them, and at the same time make the missiles of the enemy glide off them more easily.
Noah Webster's New International Dictionary of the English Language
1. (n.) A broad piece of defensive armor, carried on the arm, -- formerly in general use in war, for the protection of the body. See Buckler.
2. (n.) Anything which protects or defends; defense; shelter; protection.
3. (n.) Figuratively, one who protects or defends.
4. (n.) In lichens, a Hardened cup or disk surrounded by a rim and containing the fructification, or asci.
5. (n.) The escutcheon or field on which are placed the bearings in coats of arms. Cf. Lozenge.
6. (n.) A framework used to protect workmen in making an a ditch under ground, and capable of being pushed along as excavation progresses.
7. (n.) A spot resembling, or having the form of, a shield.
8. (n.) A coin, the old French crown, or ecu, having on one side the figure of a shield.
9. (n.) To cover with, or as with, a shield; to cover from danger; to defend; to protect from assault or injury.
10. (n.) To ward off; to keep off or out.
11. (n.) To avert, as a misfortune; hence, as a supplicatory exclamation, forbid!