enceinte (ĕn-sānt′, än-sănt′) noun
1. An enclosing wall or fortification around a fort, castle, or town.
2. The area protected by such a fortification.
Etymology: According to my dictionary, the adjective was in use by 1600, about 100 years before the noun.
The adjective comes from the French enciente (pregnant), which seems to be from Latin inciens (being with young).
The noun comes from the French enceindre (to encompass), which is from Latin cingere (to gird).
Some etymology references say the French adjective comes from the Latin incincta (ungirded).
I'm not entirely sure which is correct, nor am I sure if this origin refers to the same sort of enclosing protection as the noun,
or if it refers to the problems of girdling/belting one's clothing while pregnant.