Ramble

To walk, ride, or sail, from place to place, without any determinate object in view; to roam carelessly or irregularly; to rove; to wander; as, to ramble about the city; to ramble over the world.

To talk or write in a discursive, aimless way.

To extend or grow at random.

A going or moving from place to place without any determinate business or object; an excursion or stroll merely for recreation.

A bed of shale over the seam.