The Collaborative International Dictionary of English v.0.48:

Erection \E*rec"tion\, n. [L. erectio: cf. F. ['e]rection.]
   1. The act of erecting, or raising upright; the act of
      constructing, as a building or a wall, or of fitting
      together the parts of, as a machine; the act of founding
      or establishing, as a commonwealth or an office; also, the
      act of rousing to excitement or courage.
      [1913 Webster]

   2. The state of being erected, lifted up, built, established,
      or founded; exaltation of feelings or purposes.
      [1913 Webster]

            Her peerless height my mind to high erection draws
            up.                                   --Sidney
      [1913 Webster]

   3. State of being stretched to stiffness; tension.
      [1913 Webster]

   4. Anything erected; a building of any kind.
      [1913 Webster]

   5. (Physiol.) The state of a body part which, from having
      been soft, has become hard and swollen by the accumulation
      of blood in the erectile tissue; -- used especially of the
      penis; as, to get or have an erection.
      [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

erection
    n 1: an erect penis [syn: erection, hard-on]
    2: a structure that has been erected
    3: the act of building or putting up [syn: erecting,
       erection]

Moby Thesaurus II by Grady Ward, 1.0:

113 Moby Thesaurus words for "erection":
   Dymaxion house, White House, adobe house, apotheosis, architecture,
   ascent, assembly, assumption, beatification, building,
   canonization, casa, casting, cliff dwelling, composition,
   construct, construction, consulate, conversion, country house,
   country seat, crafting, craftsmanship, creation, cultivation,
   dacha, deanery, deification, devising, dwelling house, edifice,
   elaboration, elevation, embassy, enshrinement, erecting,
   escalation, establishment, exaltation, extraction, fabric,
   fabrication, farm, farmhouse, fashioning, formation, forming,
   formulation, framing, growing, hall, handicraft, handiwork,
   harvesting, heaving up, height, house, houseboat, lake dwelling,
   lifting, living machine, lodge, lofting, machining, making,
   manor house, manse, manufacture, manufacturing, milling, mining,
   molding, packaged house, parsonage, penthouse, pile, prefab,
   prefabricated house, prefabrication, preparation,
   presidential palace, processing, producing, pyramid, raising,
   ranch house, rearing, rectory, refining, roof, shaping, skyscraper,
   smelting, sod house, split-level, standing on end, structure,
   superstructure, sursum corda, tower, town house, upbuoying, upcast,
   upheaval, uplift, uplifting, upping, upraising, uprearing, upthrow,
   upthrust, vicarage, workmanship