Meanings of uncomprehended words in English

He sang without further preliminary, substituting a blank phrasing for uncomprehended words; but the melody swept without faltering to its conclusion.

Suddenly there carolled forth the song of a human voice,- awild ,irregular ,half-savagemelody, foreign, uncomprehended words,-airand words not new to me.

They nearly screamed in terror, for their excited imagination caused them to hear ghostly sounds,-disconnected ,uncomprehendedwords.

"I am alive," were the uncomprehended words which, upon recognizing the locality of the dissecting-room, he had endeavored, in his extremity, to utter.