The Collaborative International Dictionary of English v.0.48:

Pavilion \Pa*vil"ion\, n. [F. pavillon, fr. L. pavilio a
   butterfly, also, a tent, because spread out like a
   butterfly's wings.]
   1. A temporary movable habitation; a large tent; a marquee;
      esp., a tent raised on posts. "[The] Greeks do pitch their
      brave pavilions." --Shak.
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   2. (Arch.) A single body or mass of building, contained
      within simple walls and a single roof, whether insulated,
      as in the park or garden of a larger edifice, or united
      with other parts, and forming an angle or central feature
      of a large pile.
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   3. (Mil.) A flag, colors, ensign, or banner.
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   4. (Her.) Same as Tent (Her.)
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   5. That part of a brilliant which lies between the girdle and
      collet. See Illust. of Brilliant.
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   6. (Anat.) The auricle of the ear; also, the fimbriated
      extremity of the Fallopian tube.
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   7. A covering; a canopy; figuratively, the sky.
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            The pavilion of heaven is bare.       --Shelley.
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The Collaborative International Dictionary of English v.0.48:

Pavilion \Pa*vil"ion\, v. t. [imp. & p. p. Pavilioned; p. pr.
   & vb. n. Pavilioning.]
   To furnish or cover with, or shelter in, a tent or tents.
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         The field pavilioned with his guardians bright.
                                                  --Milton.
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WordNet (r) 3.0 (2006):

pavilion
    n 1: large and often sumptuous tent [syn: pavilion, marquee]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "pavilion":
   Nissen hut, Quonset hut, booth, crib, gatehouse, hut, hutch, kiosk,
   lean-to, outbuilding, outhouse, sentry box, shack, shanty, shed,
   stall, tollbooth, tollhouse



Easton's 1897 Bible Dictionary:

Pavilion
   a tent or tabernacle (2 Sam. 22:12; 1 Kings 20:12-16), or
   enclosure (Ps. 18:11; 27:5). In Jer. 43:10 it probably denotes
   the canopy suspended over the judgement-seat of the king.