What does the word involuntary mean?

Usage examples for involuntary

  1. After his first involuntary reply to me in German, the man had spoken in low, half- whispered tones. – The Man From the Clouds by J. Storer Clouston
  2. The last part of the sentence was involuntary. – The Allen House or Twenty Years Ago and Now by T. S. Arthur
  3. Both Mrs. Poland and Amy gave a faint and involuntary cry of alarm, but Haldane's eyes were fixed on the little smiling face that he held so near to his own. – A Knight Of The Nineteenth Century by E. P. Roe