What does the word groove mean?

Usage examples for groove

  1. This groove is continued vertically along the inside of the back- rest and foot of the tub respectively, to communicate at either end with the bed for the reception of the carbon plates. – The Electric Bath by George M. Schweig
  2. Their feet were against the groove which held the fusuma. – The Way of the Gods by John Luther Long
  3. The bowel being empty and the bladder moderately full, a staff with a groove in its left side is to be passed by the urethra into the bladder. – Surgical Anatomy by Joseph Maclise