Both Uses

monologue
in
Look Homeward, Angel
(Auto-generated)

Across the street again, before the windows of the Van W. Yeats Shoe Company, the Reverend J. Brooks Gall, Amherst ('61), and as loyal a Deke as ever breathed, but looking only sixty of his seventy-three years, paused in his brisk walk, and engaged in sprightly monologue, three of his fellow Boy Scouts—the Messrs. Lewis Monk, seventeen, Bruce Rogers, thirteen, and Malcolm Hodges, fourteen.†
Chpt 2

monologue = a long uninterrupted speech
She continued in amiable monologue for another half hour, her eyes probing about swiftly all the time at the two dark figures before her.†
Chpt 3 *

Definitions:

(1) (monologue)
a long speech by one person, whether it's a dramatic speech in a play, a run-on talk that keeps others from getting a word in, or a comedian's continuous stream of jokes and stories delivered alone

Although less frequently used, "monolog" is also a correct spelling in the United States.
(2) (meaning too rare to warrant focus)