All 4 Uses of

covert
in
The Iliad by Homer - (translated by: Butler)

Thereon he sprang covertly down for fear some of the Achaeans might see that he was wounded and taunt him.†
Book 12 *

Antilochus sprang upon him as a dog springs on a fawn which a hunter has hit as it was breaking away from its covert, and killed it.†
Book 15

As a leopardess that bounds from out a thick covert to attack a hunter—she knows no fear and is not dismayed by the baying of the hounds; even though the man be too quick for her and wound her either with thrust or spear, still, though the spear has pierced her she will not give in till she has either caught him in her grip or been killed outright—even so did noble Agenor son of Antenor refuse to fly till he had made trial of Achilles, and took aim at him with his spear, holding his round shield before him and crying with a loud voice.†
Book 21

Achilles was still in full pursuit of Hector, as a hound chasing a fawn which he has started from its covert on the mountains, and hunts through glade and thicket.†
Book 22

Definitions:

(1) (covert as in: a covert plan)
done in a secret or hidden way
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Much more rarely, covert is used as a noun to describe a hidden or sheltered place.