The Collaborative International Dictionary of English v.0.48:

Mercer \Mer"cer\, n. [F. mercier, fr. L. merx, mercis, wares,
   merchandise. See Merchant.]
   Originally, a dealer in any kind of goods or wares; now
   restricted to a dealer in textile fabrics, as silks or
   woolens. [Eng.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

mercer
    n 1: a dealer in textiles (especially silks)
    2: British maker of printed calico cloth who invented
       mercerizing (1791-1866) [syn: Mercer, John Mercer]

U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in Kentucky
   Population (2000):    20817
   Housing Units (2000): 9289
   Land area (2000):     250.915844 sq. miles (649.869025 sq. km)
   Water area (2000):    2.196707 sq. miles (5.689445 sq. km)
   Total area (2000):    253.112551 sq. miles (655.558470 sq. km)
   Located within:       Kentucky (KY), FIPS 21
   Location:             37.782987 N, 84.848614 W
   Headwords:
    Mercer
    Mercer, KY
    Mercer County
    Mercer County, KY


U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in Illinois
   Population (2000):    16957
   Housing Units (2000): 7109
   Land area (2000):     561.024464 sq. miles (1453.046630 sq. km)
   Water area (2000):    7.859359 sq. miles (20.355646 sq. km)
   Total area (2000):    568.883823 sq. miles (1473.402276 sq. km)
   Located within:       Illinois (IL), FIPS 17
   Location:             41.201226 N, 90.730320 W
   Headwords:
    Mercer
    Mercer, IL
    Mercer County
    Mercer County, IL


U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in Missouri
   Population (2000):    3757
   Housing Units (2000): 2125
   Land area (2000):     454.175881 sq. miles (1176.310082 sq. km)
   Water area (2000):    1.001537 sq. miles (2.593970 sq. km)
   Total area (2000):    455.177418 sq. miles (1178.904052 sq. km)
   Located within:       Missouri (MO), FIPS 29
   Location:             40.428383 N, 93.577593 W
   Headwords:
    Mercer
    Mercer, MO
    Mercer County
    Mercer County, MO


U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in Ohio
   Population (2000):    40924
   Housing Units (2000): 15875
   Land area (2000):     463.265405 sq. miles (1199.851841 sq. km)
   Water area (2000):    10.028853 sq. miles (25.974609 sq. km)
   Total area (2000):    473.294258 sq. miles (1225.826450 sq. km)
   Located within:       Ohio (OH), FIPS 39
   Location:             40.527317 N, 84.619566 W
   Headwords:
    Mercer
    Mercer, OH
    Mercer County
    Mercer County, OH


U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in New Jersey
   Population (2000):    350761
   Housing Units (2000): 133280
   Land area (2000):     225.929010 sq. miles (585.153425 sq. km)
   Water area (2000):    2.906802 sq. miles (7.528582 sq. km)
   Total area (2000):    228.835812 sq. miles (592.682007 sq. km)
   Located within:       New Jersey (NJ), FIPS 34
   Location:             40.252908 N, 74.711654 W
   Headwords:
    Mercer
    Mercer, NJ
    Mercer County
    Mercer County, NJ


U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in North Dakota
   Population (2000):    8644
   Housing Units (2000): 4402
   Land area (2000):     1045.488660 sq. miles (2707.803083 sq. km)
   Water area (2000):    66.934601 sq. miles (173.359813 sq. km)
   Total area (2000):    1112.423261 sq. miles (2881.162896 sq. km)
   Located within:       North Dakota (ND), FIPS 38
   Location:             47.284699 N, 101.686375 W
   Headwords:
    Mercer
    Mercer, ND
    Mercer County
    Mercer County, ND


U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in Pennsylvania
   Population (2000):    120293
   Housing Units (2000): 49859
   Land area (2000):     671.815970 sq. miles (1739.995300 sq. km)
   Water area (2000):    10.757464 sq. miles (27.861703 sq. km)
   Total area (2000):    682.573434 sq. miles (1767.857003 sq. km)
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             41.294427 N, 80.313128 W
   Headwords:
    Mercer
    Mercer, PA
    Mercer County
    Mercer County, PA


U.S. Gazetteer Counties (2000):

Mercer -- U.S. County in West Virginia
   Population (2000):    62980
   Housing Units (2000): 30143
   Land area (2000):     420.428274 sq. miles (1088.904184 sq. km)
   Water area (2000):    0.257237 sq. miles (0.666240 sq. km)
   Total area (2000):    420.685511 sq. miles (1089.570424 sq. km)
   Located within:       West Virginia (WV), FIPS 54
   Location:             37.347449 N, 81.155239 W
   Headwords:
    Mercer
    Mercer, WV
    Mercer County
    Mercer County, WV


U.S. Gazetteer Places (2000):

Mercer, MO -- U.S. town in Missouri
   Population (2000):    342
   Housing Units (2000): 193
   Land area (2000):     0.353933 sq. miles (0.916683 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.353933 sq. miles (0.916683 sq. km)
   FIPS code:            47486
   Located within:       Missouri (MO), FIPS 29
   Location:             40.511846 N, 93.529509 W
   ZIP Codes (1990):     64661
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Mercer, MO
    Mercer


U.S. Gazetteer Places (2000):

Mercer, ND -- U.S. city in North Dakota
   Population (2000):    86
   Housing Units (2000): 56
   Land area (2000):     0.215993 sq. miles (0.559420 sq. km)
   Water area (2000):    0.007651 sq. miles (0.019816 sq. km)
   Total area (2000):    0.223644 sq. miles (0.579236 sq. km)
   FIPS code:            52340
   Located within:       North Dakota (ND), FIPS 38
   Location:             47.490594 N, 100.711254 W
   ZIP Codes (1990):     58559
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Mercer, ND
    Mercer


U.S. Gazetteer Places (2000):

Mercer, PA -- U.S. borough in Pennsylvania
   Population (2000):    2391
   Housing Units (2000): 1086
   Land area (2000):     1.238687 sq. miles (3.208185 sq. km)
   Water area (2000):    0.004294 sq. miles (0.011121 sq. km)
   Total area (2000):    1.242981 sq. miles (3.219306 sq. km)
   FIPS code:            48696
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             41.226347 N, 80.237436 W
   ZIP Codes (1990):     16137
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Mercer, PA
    Mercer