tool

n.

1. An implement

   implement, utensil, machine, instrument, mechanism, weapon, apparatus, appliance, engine, means, contrivance, gadget; see also device 1.

   Common tools include: can opener, hammer, mallet, knife, adz, vise, auger, lathe, router, sander, scraper, trowel, awl, hoe, shovel, rake, spade, jack, crank, pulley, wheel, bar, crowbar, lever, sledge, winch, cam, loom, shuttle, chisel, plane, screw, brace, bit, file, saw, drill, square, chisel, shears, screwdriver, wrench, pliers, tweezers, punch, level, scissors, ax, hatchet, corkscrew, jimmy.

2. One who permits himself to be used

   accessory, auxiliary, accomplice, hireling, dupe, intermediary, cat's-paw, medium, vehicle, agent, go-between, messenger, easy mark, stool pigeon*, jay*, hayseed*, greenhorn*, sucker*, patsy*, stooge*, come-on*, tuna*; see also servant.

tool is commonly applied to manual implements such as are used in carpentry, plumbing, etc.; implement applies to any device used to carry on some work or effect some purpose agricultural implements; instrument specifically implies use for delicate work or for scientific or artistic purposes surgical instruments and may also be applied, as are tool and implement, to a thing or person serving as a means to an end; appliance specifically suggests a mechanical or power-driven device, esp. one for household use; utensil is used of any implement or container for domestic use, esp. a pot, pan, etc.