The Collaborative International Dictionary of English v.0.48:

Hoop \Hoop\, n. [OE. hope; akin to D. hoep, hoepel.]
   1. A pliant strip of wood or metal bent in a circular form,
      and united at the ends, for holding together the staves of
      casks, tubs, etc.
      [1913 Webster]

   2. A ring; a circular band; anything resembling a hoop, as
      the cylinder (cheese hoop) in which the curd is pressed in
      making cheese.
      [1913 Webster]

   3. A circle, or combination of circles, of thin whalebone,
      metal, or other elastic material, used for expanding the
      skirts of ladies' dresses; crinoline; -- used chiefly in
      the plural.
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            Though stiff with hoops, and armed with ribs of
            whale.                                --Pope.
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   4. A quart pot; -- so called because originally bound with
      hoops, like a barrel. Also, a portion of the contents
      measured by the distance between the hoops. [Obs.]
      [1913 Webster]

   5. An old measure of capacity, variously estimated at from
      one to four pecks. [Eng.] --Halliwell.
      [1913 Webster]

   Bulge hoop, Chine hoop, Quarter hoop, the hoop nearest
      the middle of a cask, that nearest the end, and the
      intermediate hoop between these two, respectively.

   Flat hoop, a wooden hoop dressed flat on both sides.

   Half-round hoop, a wooden hoop left rounding and undressed
      on the outside.

   Hoop iron, iron in thin narrow strips, used for making
      hoops.

   Hoop lock, the fastening for uniting the ends of wooden
      hoops by notching and interlocking them.

   Hoop skirt, a framework of hoops for expanding the skirts
      of a woman's dress; -- called also hoop petticoat.

   Hoop snake (Zool.), a harmless snake of the Southern United
      States (Abaster erythrogrammus); -- so called from the
      mistaken notion that it curves itself into a hoop, taking
      its tail into its mouth, and rolls along with great
      velocity.

   Hoop tree (Bot.), a small West Indian tree (Melia
      sempervirens), of the Mahogany family.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hoopoe \Hoop"oe\, Hoopoo \Hoop"oo\, n. [So called from its cry;
   cf. L. upupa, Gr. ?, D. hop, F. huppe; cf. also G.
   wiedenhopf, OHG. wituhopfo, lit., wood hopper.] (Zool.)
   A European bird of the genus Upupa (Upupa epops), having
   a beautiful crest, which it can erect or depress at pleasure,
   and a slender down-curving bill. Called also hoop, whoop.
   The name is also applied to several other species of the same
   genus and allied genera.

The Collaborative International Dictionary of English v.0.48:

Hoop \Hoop\, v. t. [imp. & p. p. Hooped; p. pr. & vb. n.
   Hooping.]
   1. To bind or fasten with hoops; as, to hoop a barrel or
      puncheon.
      [1913 Webster]

   2. To clasp; to encircle; to surround. --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hoop \Hoop\, v. i. [OE. houpen; cf. F. houper to hoop, to shout;
   -- a hunting term, prob. fr. houp, an interj. used in
   calling. Cf. Whoop.]
   1. To utter a loud cry, or a sound imitative of the word, by
      way of call or pursuit; to shout. [Usually written
      whoop.]
      [1913 Webster]

   2. To whoop, as in whooping cough. See Whoop.
      [1913 Webster]

   Hooping cough. (Med.) See Whooping cough.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hoop \Hoop\, v. t. [Written also whoop.]
   1. To drive or follow with a shout. "To be hooped out of
      Rome." --Shak.
      [1913 Webster]

   2. To call by a shout or peculiar cry.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hoop \Hoop\, n.
   1. A shout; a whoop, as in whooping cough.
      [1913 Webster]

   2. (Zool.) The hoopoe. See Hoopoe.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hoop
    n 1: a light curved skeleton to spread out a skirt
    2: a rigid circular band of metal or wood or other material used
       for holding or fastening or hanging or pulling; "there was
       still a rusty iron hoop for tying a horse" [syn: hoop,
       ring]
    3: a small arch used as croquet equipment [syn: wicket,
       hoop]
    4: horizontal circular metal hoop supporting a net through which
       players try to throw the basketball [syn: basket,
       basketball hoop, hoop]
    v 1: bind or fasten with a hoop; "hoop vats"

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "hoop":
   anklet, armlet, band, belt, bracelet, cincture, cingulum, collar,
   collarband, earring, ecliptic, equator, fascia, fillet,
   finger ring, girdle, girt, girth, great circle, neckband, necklace,
   nose ring, quoit, ring, wristband, wristlet, zodiac, zone