The Collaborative International Dictionary of English v.0.48:

Juniper \Ju"ni*per\, n. [L. juniperus, prop., youth-producing,
   and so called from its evergreen appearance, from the roots
   of E. juvenile, and parent. Cf. Gin the liquor.] (Bot.)
   Any evergreen shrub or tree, of the genus Juniperus and
   order Conifer[ae].
   [1913 Webster]

   Note: The common juniper (Juniperus communis) is a shrub of
         a low, spreading form, having awl-shaped, rigid leaves
         in whorls of threes, and bearing small purplish blue
         berries (or galbuli), of a warm, pungent taste, used as
         diuretic and in flavoring gin. A resin exudes from the
         bark, which has erroneously been considered identical
         with sandarach, and is used as pounce. The oil of
         juniper is acrid, and used for various purposes, as in
         medicine, for making varnish, etc. The wood of several
         species is of a reddish color, hard and durable, and is
         used in cabinetwork under the names of red cedar,
         Bermuda cedar, etc.
         [1913 Webster]

   Juniper worm (Zool.), the larva of a geometrid moth
      (Drepanodes varus). It feeds upon the leaves of the
      juniper, and mimics the small twigs both in form and
      color, in a remarkable manner.
      [1913 Webster]

WordNet (r) 3.0 (2006):

juniper
    n 1: desert shrub of Syria and Arabia having small white
         flowers; constitutes the juniper of the Old Testament;
         sometimes placed in genus Genista [syn: retem, raetam,
         juniper bush, juniper, Retama raetam, Genista
         raetam]
    2: coniferous shrub or small tree with berrylike cones

Easton's 1897 Bible Dictionary:

Juniper
   (Heb. rothem), called by the Arabs retem, and known as Spanish
   broom; ranked under the genus genista. It is a desert shrub, and
   abounds in many parts of Palestine. In the account of his
   journey from Akabah to Jerusalem, Dr. Robinson says: "This is
   the largest and most conspicuous shrub of these deserts, growing
   thickly in the water-courses and valleys. Our Arabs always
   selected the place of encampment, if possible, in a spot where
   it grew, in order to be sheltered by it at night from the wind;
   and during the day, when they often went on in advance of the
   camels, we found them not unfrequently sitting or sleeping under
   a bush of retem to shelter them from the sun. It was in this
   very desert, a day's journey from Beersheba, that the prophet
   Elijah lay down and slept beneath the same shrub" (1 Kings 19:4,
   5). It afforded material for fuel, and also in cases of
   extremity for human food (Ps. 120:4; Job 30:4). One of the
   encampments in the wilderness of Paran is called Rithmah, i.e.,
   "place of broom" (Num. 33:18).

     "The Bedawin of Sinai still burn this very plant into a
   charcoal which throws out the most intense heat."