The Collaborative International Dictionary of English v.0.48:

Halfway \Half"way`\ (h[aum]f"w[=a]`), adv.
   In the middle; at half the distance; imperfectly; partially;
   as, he halfway yielded.
   [1913 Webster]

         Temples proud to meet their gods halfway. --Young.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Halfway \Half"way`\, a.
   Equally distant from the extremes; situated at an
   intermediate point; midway; as, at the halfway mark. [WordNet
   sense 1]

   Syn: center(prenominal), middle(prenominal), midway.
        [1913 Webster]

   2. partial. [WordNet sense 2]
      [WordNet 1.5 +PJC]

   3. including only half or a portion; incomplete; as, halfway
      measures. [WordNet sense 3]
      [WordNet 1.5 +PJC]

   Halfway covenant, a practice among the Congregational
      churches of New England, between 1657 and 1662, of
      permitting baptized persons of moral life and orthodox
      faith to enjoy all the privileges of church membership,
      save the partaking of the Lord's Supper. They were also
      allowed to present their children for baptism.
      [1913 Webster]

WordNet (r) 3.0 (2006):

halfway
    adv 1: at half the distance; at the middle; "he was halfway down
           the ladder when he fell" [syn: halfway, midway]
    adj 1: equally distant from the extremes [syn: center(a),
           halfway, middle(a), midway]
    2: at a point midway between two extremes; "at the halfway mark"
    3: including only half or a portion; "halfway measures"

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "halfway":
   amidships, average, betwixt and between, center, centermost,
   central, core, equatorial, equidistant, half, half-and-half,
   in medias res, in the mean, in the middle, interior, intermediary,
   intermediate, mean, medial, medially, median, mediocre,
   mediterranean, medium, mediumly, mesial, mezzo, mezzo-mezzo, mid,
   middle, middlemost, middling, midland, midmost, midships, midway,
   nuclear, one-and-a-half, part, partial, partly



U.S. Gazetteer Places (2000):

Halfway, MO -- U.S. village in Missouri
   Population (2000):    176
   Housing Units (2000): 74
   Land area (2000):     2.135612 sq. miles (5.531209 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    2.135612 sq. miles (5.531209 sq. km)
   FIPS code:            29962
   Located within:       Missouri (MO), FIPS 29
   Location:             37.617973 N, 93.233218 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Halfway, MO
    Halfway


U.S. Gazetteer Places (2000):

Halfway, OR -- U.S. city in Oregon
   Population (2000):    337
   Housing Units (2000): 196
   Land area (2000):     0.426876 sq. miles (1.105604 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.426876 sq. miles (1.105604 sq. km)
   FIPS code:            31650
   Located within:       Oregon (OR), FIPS 41
   Location:             44.878209 N, 117.110659 W
   ZIP Codes (1990):     97834
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Halfway, OR
    Halfway


U.S. Gazetteer Places (2000):

Halfway, MD -- U.S. Census Designated Place in Maryland
   Population (2000):    10065
   Housing Units (2000): 4424
   Land area (2000):     4.686602 sq. miles (12.138243 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    4.686602 sq. miles (12.138243 sq. km)
   FIPS code:            36125
   Located within:       Maryland (MD), FIPS 24
   Location:             39.616346 N, 77.765562 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Halfway, MD
    Halfway