"Ghillie" is the gaelic word for "servant", although modern usage is entirely for the servant who goes out with you, carrying your gun, pointing out where the grouse or salmon or trout is lying, helps you point your gun at it, or where to wave your rod, tells you when and where to fire or strike, and then substitutes "one he caught earlier" (Brit "Blue Peter" in-joke) so that you can go home boasting of your prowess as a hunter.