The Collaborative International Dictionary of English v.0.48:

Jacobus \Ja*co"bus\, n.; pl. Jacobuses. [See Jacobite.]
   An English gold coin, of the value of twenty-five shillings
   sterling, struck in the reign of James I.
   [1913 Webster]

U.S. Gazetteer Places (2000):

Jacobus, PA -- U.S. borough in Pennsylvania
   Population (2000):    1203
   Housing Units (2000): 500
   Land area (2000):     0.914121 sq. miles (2.367562 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.914121 sq. miles (2.367562 sq. km)
   FIPS code:            37640
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             39.882516 N, 76.712068 W
   ZIP Codes (1990):     17407
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Jacobus, PA
    Jacobus