noun
Meaning 1
A device used in the making of a loud-speaking telephone, depending on the fact that the friction between a metallic point and a moving cylinder of moistened chalk, or a moving slip of paper, on which it rests is diminished by the passage of a current between the point and the moving surface.
Definition source: English Wiktionary via Wiktextract
Usage: historical
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided