feme covert (n.)

"hidden, private, secret, concealed," c. 1300, from Old French covert (Modern French couvert) "hidden, obscure, underhanded," literally "covered," past participle of covrir "to cover" (see cover (v.)). Related: Covertly.

early 13c., "a cover or covering" (earliest reference is to bedcovers), from Old French coverture (12c.) "blanket; roof; concealment," from Latin *coopertura, from past participle stem of cooperire "to cover" (see cover (v.)). From late 14c. as "a protective device, a refuge." In old law, "the state of a married woman considered as under the power and protection of her husband" (1540s).

At common law coverture disabled a woman from making contracts to the prejudice of herself or her husband without his allowance or confirmation. [Century Dictionary]