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.

Vine's Expository Dictionary of New Testament Words