The Collaborative International Dictionary of English v.0.48:

Grinder \Grind"er\, n.
   1. One who, or that which, grinds.
      [1913 Webster]

   2. One of the double teeth, used to grind or masticate the
      food; a molar.
      [1913 Webster]

   3. (Zool.) The restless flycatcher (Seisura inquieta) of
      Australia; -- called also restless thrush and volatile
      thrush. It makes a noise like a scissors grinder, to
      which the name alludes.

   4. A submarine sandwich. [local, U.S.]

   Syn: submarine, hoagie.
        [PJC]

   Grinder's asthma, Grinder's phthisis, or Grinder's rot
      (Med.), a lung disease produced by the mechanical
      irritation of the particles of steel and stone given off
      in the operation of grinding.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

hoagie \hoagie\, hoagy \hoagy\n.
   a large sandwich on a long crusty roll that is split
   lengthwise and filled with meats and cheese (and tomato and
   onion and lettuce and condiments); different names are used
   in different sections of the U. S., such as hero,
   grinder, and submarine.

   Syn: bomber, grinder, hero, hero sandwich, hoagie, Cuban
        sandwich, Italian sandwich, poor boy, sub, submarine,
        submarine sandwich, torpedo, wedge, zep.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

submarine sandwich \sub`ma*rine" sand"wich\, n.
   A large sandwich on an elongated roll, usually incompletely
   cut into two halves, filed with various cold cuts, meatballs,
   lettuce, cheese, tomatoes, olives, etc., and spiced
   variously, and often having oil or other dressing applied;
   called also hoagie, hero, hero sandwich, grinder,
   sub, submarine, poor boy, and Italian sandwich. A
   single such sandwich may consitute a substantial meal. Very
   large variants are sometimes prepared for social gatherings
   and cut into pieces for individual consumption.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Sub \Sub\, n.
   1. A subordinate; a subaltern. [Colloq.]
      [1913 Webster]

   2. a shortened form of submarine, the boat.
      [PJC]

   3. a shortened form of submarine sandwich; also called
      hero, hero sandwich, and grinder.
      [PJC]

WordNet (r) 3.0 (2006):

grinder
    n 1: a large sandwich made of a long crusty roll split
         lengthwise and filled with meats and cheese (and tomato and
         onion and lettuce and condiments); different names are used
         in different sections of the United States [syn: bomber,
         grinder, hero, hero sandwich, hoagie, hoagy,
         Cuban sandwich, Italian sandwich, poor boy, sub,
         submarine, submarine sandwich, torpedo, wedge,
         zep]
    2: grinding tooth with a broad crown; located behind the
       premolars [syn: molar, grinder]
    3: machinery that processes materials by grinding or crushing
       [syn: mill, grinder, milling machinery]
    4: a machine tool that polishes metal

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "grinder":
   BLT, Dagwood sandwich, Sloppy Joe, Swiss cheese sandwich,
   baby tooth, bacon-lettuce-tomato sandwich, bicuspid, bucktooth,
   canape, canine, cheese grater, cheeseburger, comminutor,
   corned beef sandwich, crown, crusher, cuspid, cutter,
   deciduous tooth, dent, denticle, denticulation, dentil, dentition,
   dogtooth, double-decker sandwich, egg salad sandwich, eyetooth,
   fang, fore tooth, gagtooth, gang tooth, gold tooth, granulator,
   grater, grilled cheese sandwich, ham sandwich, hamburger, hoagy,
   hot dog, incisor, kominuter, levigator, masher, milk tooth, mill,
   millstone, molar, mortar and pestle, nutmeg grater,
   pastrami sandwich, peg, permanent tooth, pestle, pivot tooth,
   poor boy, premolar, pulverizer, quern, quernstone, rock crusher,
   roller, sandwich, scrivello, shredder, snag, snaggletooth,
   steamroller, submarine sandwich, tooth, triturator,
   tuna salad sandwich, tunaburger, tush, tusk, wisdom tooth