The Collaborative International Dictionary of English v.0.48:

Myrtle \Myr"tle\ (m[~e]r"t'l), n. [F. myrtil bilberry, prop., a
   little myrtle, from myrte myrtle, L. myrtus, murtus, Gr.
   my`rtos; cf. Per. m[=u]rd.] (Bot.)
   A species of the genus Myrtus, especially Myrtus
   communis. The common myrtle has a shrubby, upright stem,
   eight or ten feet high. Its branches form a close, full head,
   thickly covered with ovate or lanceolate evergreen leaves. It
   has solitary axillary white or rosy flowers, followed by
   black several-seeded berries. The ancients considered it
   sacred to Venus. The flowers, leaves, and berries are used
   variously in perfumery and as a condiment, and the
   beautifully mottled wood is used in turning.
   [1913 Webster]

   Note: The name is also popularly but wrongly applied in
         America to two creeping plants, the blue-flowered
         periwinkle and the yellow-flowered moneywort. In the
         West Indies several myrtaceous shrubs are called
         myrtle.
         [1913 Webster]

   Bog myrtle, the sweet gale.

   Crape myrtle. See under Crape.

   Myrtle warbler (Zool.), a North American wood warbler
      (Dendroica coronata); -- called also myrtle bird,
      yellow-rumped warbler, and yellow-crowned warbler.

   Myrtle wax. (Bot.) See Bayberry tallow, under Bayberry.


   Sand myrtle, a low, branching evergreen shrub (Leiophyllum
      buxifolium), growing in New Jersey and southward.

   Wax myrtle (Myrica cerifera). See Bayberry.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Warbler \War"bler\, n.
   1. One who, or that which, warbles; a singer; a songster; --
      applied chiefly to birds.
      [1913 Webster]

            In lulling strains the feathered warblers woo.
                                                  --Tickell.
      [1913 Webster]

   2. (Zool.) Any one of numerous species of small Old World
      singing birds belonging to the family Sylviidae, many of
      which are noted songsters. The bluethroat, blackcap, reed
      warbler (see under Reed), and sedge warbler (see under
      Sedge) are well-known species.
      [1913 Webster]

   3. (Zool.) Any one of numerous species of small, often bright
      colored, American singing birds of the family or subfamily
      Mniotiltidae, or Sylvicolinae. They are allied to the
      Old World warblers, but most of them are not particularly
      musical.
      [1913 Webster]

   Note: The American warblers are often divided, according to
         their habits, into bush warblers, creeping warblers,
         fly-catching warblers, ground warblers, wood warblers,
         wormeating warblers, etc.
         [1913 Webster]

   Bush warbler (Zool.) any American warbler of the genus
      Opornis, as the Connecticut warbler (Opornis agilis).


   Creeping warbler (Zool.), any one of several species of
      very small American warblers belonging to Parula,
      Mniotilta, and allied genera, as the blue yellow-backed
      warbler (Parula Americana), and the black-and-white
      creeper (Mniotilta varia).

   Fly-catching warbler (Zool.), any one of several species of
      warblers belonging to Setophaga, Sylvania, and allied
      genera having the bill hooked and notched at the tip, with
      strong rictal bristles at the base, as the hooded warbler
      (Sylvania mitrata), the black-capped warbler (Sylvania
      pusilla), the Canadian warbler (Sylvania Canadensis),
      and the American redstart (see Redstart).

   Ground warbler (Zool.), any American warbler of the genus
      Geothlypis, as the mourning ground warbler (Geothlypis
      Philadelphia), and the Maryland yellowthroat (see
      Yellowthroat).

   Wood warbler (Zool.), any one of numerous American warblers
      of the genus Dendroica. Among the most common wood
      warblers in the Eastern States are the yellowbird, or
      yellow warbler (see under Yellow), the black-throated
      green warbler (Dendroica virens), the yellow-rumped
      warbler (Dendroica coronata), the blackpoll (Dendroica
      striata), the bay-breasted warbler (Dendroica
      castanea), the chestnut-sided warbler (Dendroica
      Pennsylvanica), the Cape May warbler (Dendroica
      tigrina), the prairie warbler (see under Prairie), and
      the pine warbler (Dendroica pinus). See also Magnolia
      warbler, under Magnolia, and Blackburnian warbler.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Dendroica coronata
    n 1: similar to Audubon's warbler [syn: myrtle warbler,
         myrtle bird, Dendroica coronata]