What does the word gear mean?

Usage examples for gear

  1. Divide the number of teeth in the wheel to be marked by the number of teeth in the wheel with which it gears, and multiply by the degree of flank curve selected for the wheel with which that to be marked is to gear, and this will give the ratio. – Modern Machine-Shop Practice, Volumes I and II by Joshua Rose
  2. Do you still strip a gear on this thing every time you try to back? – Homeburg Memories by George Helgesen Fitch
  3. I hadn't had any loose ends to tie up in the Trade City, since I'd already disposed of most of my gear before boarding the starship. – The Door Through Space by Marion Zimmer Bradley