verb

• (intransitive) To talk rapidly, indistinctly, or unintelligibly; to utter gibberish or nonsense.
  "1829, James Hogg, The Shepherd’s Calendar, New York: A.T. Goodrich, Volume I, Chapter 9, “Mary Burnet,” p. 184, Allanson made some sound in his throat, as if attempting to speak, but his tongue refused its office, and he only jabbered."
• (transitive) To utter rapidly or indistinctly; to gabble.
  "She had Lord James' collar in one big fist and she pounded the table with the other and talked a blue streak. Nobody could make out plain what she said, for she was mainly jabbering Swede lingo, but there was English enough, of a kind, to give us some idee."

noun

• (informal) One who administers a hypodermic injection.
  "Like Claire, these “secret jabbers” are keeping it private even from their closest family and friends."