Tracker \Track"er\, n.

1. One who, or that which, tracks or pursues, as a man or dog that follows game.

And of the trackers of the deer Scarce half the lessening pack was near. --Sir W. Scott.

2. (Mus.) In the organ, a light strip of wood connecting (in path) a key and a pallet, to communicate motion by pulling.

Source: Webster's Revised Unabridged Dictionary (1913)