The Collaborative International Dictionary of English v.0.48:

fountainhead \fountainhead\ n.
   1. an abundant source.

   Syn: well, wellspring.
        [WordNet 1.5]

   2. the source of water from which a stream arises.

   Syn: headspring, head.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

fountainhead
    n 1: an abundant source; "she was a well of information" [syn:
         well, wellspring, fountainhead]
    2: the source of water from which a stream arises; "they tracked
       him back toward the head of the stream" [syn: fountainhead,
       headspring, head]

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "fountainhead":
   font, fount, fountain, head, headspring, headstream, headwater,
   headwaters, inception, mainspring, mine, origin, provenance,
   provenience, quarry, riverhead, root, source, spring, springhead,
   well, wellhead, wellspring, whence



U.S. Gazetteer Places (2000):

Fountainhead-Orchard Hills, MD -- U.S. Census Designated Place in Maryland
   Population (2000):    3844
   Housing Units (2000): 1621
   Land area (2000):     3.816091 sq. miles (9.883629 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    3.816091 sq. miles (9.883629 sq. km)
   FIPS code:            29712
   Located within:       Maryland (MD), FIPS 24
   Location:             39.682933 N, 77.716526 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Fountainhead-Orchard Hills, MD
    Fountainhead-Orchard Hills
    Fountainhead, MD
    Fountainhead