The Collaborative International Dictionary of English v.0.48:

Terrace \Ter"race\, v. t. [imp. & p. p. Terraced; p. pr. & vb.
   n. Terracing.]
   To form into a terrace or terraces; to furnish with a terrace
   or terraces, as, to terrace a garden, or a building. --Sir H.
   Wotton.
   [1913 Webster]

         Clermont's terraced height, and Esher's groves.
                                                  --Thomson.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Terrace \Ter"race\, n. [F. terrasse (cf. Sp. terraza, It.
   terrazza), fr. L. terra the earth, probably for tersa,
   originally meaning, dry land, and akin to torrere to parch,
   E. torrid, and thirst. See Thirst, and cf. Fumitory,
   Inter, v., Patterre, Terrier, Trass, Tureen,
   Turmeric.]
   1. A raised level space, shelf, or platform of earth,
      supported on one or more sides by a wall, a bank of tuft,
      or the like, whether designed for use or pleasure.
      [1913 Webster]

   2. A balcony, especially a large and uncovered one.
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   3. A flat roof to a house; as, the buildings of the Oriental
      nations are covered with terraces.
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   4. A street, or a row of houses, on a bank or the side of a
      hill; hence, any street, or row of houses.
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   5. (Geol.) A level plain, usually with a steep front,
      bordering a river, a lake, or sometimes the sea.
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   Note: Many rivers are bordered by a series of terraces at
         different levels, indicating the flood plains at
         successive periods in their history.
         [1913 Webster]

   Terrace epoch. (Geol.) See Drift epoch, under Drift, a.
      [1913 Webster]

WordNet (r) 3.0 (2006):

terrace
    n 1: usually paved outdoor area adjoining a residence [syn:
         patio, terrace]
    2: a level shelf of land interrupting a declivity (with steep
       slopes above and below) [syn: terrace, bench]
    3: a row of houses built in a similar style and having common
       dividing walls (or the street on which they face); "Grosvenor
       Terrace"
    v 1: provide (a house) with a terrace; "We terrassed the country
         house" [syn: terrace, terrasse]
    2: make into terraces as for cultivation; "The Incas terraced
       their mountainous land"

Moby Thesaurus II by Grady Ward, 1.0:

128 Moby Thesaurus words for "terrace":
   Autobahn, US highway, alley, alleyway, arterial, arterial highway,
   arterial street, artery, autoroute, autostrada, avenue, balcony,
   belt highway, billiard table, blind alley, boulevard,
   bowling green, bypass, byway, camino real, carriageway, catafalque,
   causeway, causey, chaussee, circumferential, close, corduroy road,
   county road, court, crescent, cul-de-sac, dais, dead flat,
   dead level, dead-end street, dike, dirt road, drive, driveway,
   earth, emplacement, esplanade, estrade, expressway, flat, flatland,
   floor, freeway, gallery, gravel road, ground, heliport, highroad,
   highway, highways and byways, homaloid, horizontal,
   horizontal axis, horizontal fault, horizontal line,
   horizontal parallax, horizontal plane, horizontal projection,
   hustings, interstate highway, landing, landing pad, landing stage,
   lane, launching pad, ledge, level, level line, level plane,
   local road, main drag, main road, mean sea level, mews, motorway,
   parkway, parterre, pave, paved road, pike, place, plain, plane,
   plank road, platform, podium, prairie, primary highway,
   private road, pulpit, right-of-way, ring road, road, roadbed,
   roadway, rostrum, route nationale, row, royal road, sea level,
   sea of grass, secondary road, soapbox, speedway, stage,
   state highway, step terrace, steppe, street, stump, superhighway,
   table, thoroughfare, through street, thruway, toll road,
   township road, tribunal, tribune, turnpike, water level, wynd