Definitions of covert:

• noun:   a flock of coots
• noun:   a covering that serves to conceal or shelter something
• adjective:   secret or hidden; not openly practiced or engaged in or shown or avowed

  Example: "Covert actions by the CIA"

• adjective:   of a wife; under the protection of her husband
• name:  A surname (rare: 1 in 33333 families; popularity rank in the U.S.: #3936)