cloak, cloaca

Cloak or cloak means a cape or a loose coat --
He wrapped his cloak about him, and went out into the storm.
"And if any man will sue thee at the law, and take away thy coat, let him have thy cloak also."
It's a good old-fashioned cloak and dagger story.
He hides behind a cloak of indifference, even apathy.

Cloak may also mean to cover, as with a cape or coat, literally or figuratively --
They used leaves to cloak their nakedness.
He uses hostility to cloak his shame.

Cloaca or cloaca means an ancient sewer or some other waste receptacle, such as a privy --
Some parts of the Cloaca Maxima, built by the Romans, are still intact.
The cloaca drained waste into the river.

Cloaca also means a body cavity in birds, reptiles, and some other creatures, used for waste and to give birth or to lay eggs --
If there are eggs in the cloaca, the frog is a female.
Both male and female reptiles have a cloaca.

Now that you know that, you can say --
"Low branches and tall grass sometimes cloak the entrance to the ancient cloaca."