Yet, during my all-too-short time there, the charms of the country and its people began to seep under my defenses.
The missile that had been readied on the launch ramp in France made it through the defenses.
Something in her wiring has taught her that relaxing her defenses is dangerous.
c.1300, "forbidding, prohibition," also "action of guarding or protecting," from Old French defense, from Latin defensus, past participle of defendere "ward off, protect" (see defend). But it also arrived (without the final -e) from Old French defens, from Latin defensum "thing protected or forbidden," neuter past participle of defendere.
Defens was assimilated into defense, but not before it inspired the alternative spelling defence, via the same tendency that produced hence (hennis), pence (penies), dunce (Duns). First used 1935 as a euphemism for "national military resources." Defense mechanism in psychology is from 1913.
defense de·fense (dĭ-fěns')
A means or method that helps protect the body or mind, as against disease or anxiety.