Shield - Vine's Expository Dictionary of New Testament Words
Shield
[ 1,,G2375, thureos ]formerly meant a stone for closing the entrance of a cave;" then, "a shield," large and oblong, protecting every part of the soldier; the word is used metaphorically of faith, Ephesians 6:16, which the believer is to take up "in (en in the original) all" (all that has just been mentioned), i.e., as affecting the whole of his activities.