The Collaborative International Dictionary of English v.0.48:

Highway \High"way`\, n.
   A road or way open to the use of the public, especially a
   paved main road or thoroughfare between towns; in the latter
   sense it contrasts with local street; as, on the highways
   and byways.

   Syn: Way; road; path; course.
        [1913 Webster]

WordNet (r) 3.0 (2006):

highway
    n 1: a major road for any form of motor transport [syn:
         highway, main road]

Moby Thesaurus II by Grady Ward, 1.0:

78 Moby Thesaurus words for "highway":
   Autobahn, US highway, alley, alleyway, arterial, arterial highway,
   arterial street, artery, autoroute, autostrada, avenue,
   belt highway, blind alley, boulevard, bypass, byway, camino real,
   carriageway, causeway, causey, chaussee, circumferential, close,
   corduroy road, county road, court, crescent, cul-de-sac,
   dead-end street, dike, dirt road, drag, drive, driveway,
   expressway, freeway, gravel road, highroad, highways and byways,
   interstate highway, lane, local road, main drag, main road, mews,
   motorway, parkway, path, pave, paved road, pike, place, plank road,
   primary highway, private road, right-of-way, ring road, road,
   roadbed, roadway, route nationale, row, royal road, secondary road,
   speedway, state highway, street, superhighway, terrace,
   thoroughfare, through street, thruway, toll road, township road,
   track, turnpike, way, wynd



Easton's 1897 Bible Dictionary:

Highway
   a raised road for public use. Such roads were not found in
   Palestine; hence the force of the language used to describe the
   return of the captives and the advent of the Messiah (Isa.
   11:16; 35:8; 40:3; 62:10) under the figure of the preparation of
   a grand thoroughfare for their march.

     During their possession of Palestine the Romans constructed
   several important highways, as they did in all countries which
   they ruled.


Bouvier's Law Dictionary, Revised 6th Ed (1856):

HIGHWAY. A passage or road through the country, or some parts of it, for the
use of the people. 1 Bouv. Inst. n. 442. The term highway is said to be a
generic name for all kinds of public ways. 6 Mod R, 255.
     2. Highways are universally laid out by public authority and repaired
at the public expense, by direction of law. 4 Burr. Rep. 2511.
     3. The public have an easement over a highway, of which the owner of
the land cannot deprive them; but the soil and freehold still remain in the
owner, and he may use the land above and below consistently with the
easement. He may, therefore, work a mine, sink a drain or water course,
under the highway, if the easement remains unimpaired. Vide Road; Street;
Way; and 4 Vin. Ab. 502; Bac. Ab. h.t.; Com. Dig. Chemin; Dane's Ab. Index,
h.t.; Egremont on Highways; Wellbeloved on Highways; Woolrych on Ways; 1 N.
H. Rep. 16; 1 Conn. R. 103; 1 Pick. R. 122; 1 M'Cord's R. 67; 2 Mass. R.
127; 1 Pick. R. 122; 3 Rawle, R. 495; 15 John. R. 483; 16 Mass. R. 33; 1
Shepl. R. 250; 4 Day, R. 330; 2 Bail. R. 271; 1 Yeates, Rep. 167.
     4. The owners of lots on opposite sides of a highway, are prima facie
owners, each of one half of the highway,, 9 Serg. & Rawle, 33; Ham. Parties,
275; Bro. Abr. Nuisance, pl. 18 and the owner may recover the possession in
ejectment, and have it delivered to him, subject to the public easement.
Adams on Eject. 19, 18; 2 Johns. Rep. 357; 15 Johns. Rep. 447; 6 Mass. 454;
2 Mass. 125.
     5. If the highway is impassable, the public have the right to pass over
the adjacent soil; but this rule does not extend to private ways, without an
express grant. Morg. Vad. Mec. 456-7; 1 Tho. Co. Lit. 275; note 1 Barton,
Elem. Conv. 271; Yelv. 142, note 1.