The Collaborative International Dictionary of English v.0.48:

Friar \Fri"ar\, n. [OR. frere, F. fr[`e]re brother, friar, fr.
   L. frater brother. See Brother.]
   1. (R. C. Ch.) A brother or member of any religious order,
      but especially of one of the four mendicant orders, viz:
      (a) Minors, Gray Friars, or Franciscans. (b)
      Augustines. (c) Dominicans or Black Friars. (d) White
      Friars or Carmelites. See these names in the Vocabulary.
      [1913 Webster]

   2. (Print.) A white or pale patch on a printed page.
      [1913 Webster]

   3. (Zool.) An American fish; the silversides.
      [1913 Webster]

   Friar bird (Zool.), an Australian bird (Tropidorhynchus
      corniculatus), having the head destitute of feathers; --
      called also coldong, leatherhead, pimlico; poor
      soldier, and four-o'clock. The name is also applied to
      several other species of the same genus.

   Friar's balsam (Med.), a stimulating application for wounds
      and ulcers, being an alcoholic solution of benzoin,
      styrax, tolu balsam, and aloes; compound tincture of
      benzoin. --Brande & C.

   Friar's cap (Bot.), the monkshood.

   Friar's cowl (Bot.), an arumlike plant (Arisarum vulgare)
      with a spathe or involucral leaf resembling a cowl.

   Friar's lantern, the ignis fatuus or Will-o'-the-wisp.
      --Milton.

   Friar skate (Zool.), the European white or sharpnosed skate
      (Raia alba); -- called also Burton skate, border
      ray, scad, and doctor.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Four-o'clock \Four"-o'clock`\, n.
   1. (Bot.) A plant of the genus Mirabilis. There are about
      half a dozen species, natives of the warmer parts of
      America. The common four-o'clock is M. Jalapa. Its
      flowers are white, yellow, and red, and open toward
      sunset, or earlier in cloudy weather; hence the name. It
      is also called marvel of Peru, and afternoon lady.
      [1913 Webster]

   2. (Zool.) The friar bird; -- so called from its cry, which
      resembles these words.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

marvel of Peru \marvel of Peru\, marvel-of-Peru \marvel-of-Peru\
   n. (Bot.)
   A common garden plant (Mirabilis jalapa or Mirabilis
   uniflora) of North America having fragrant red or purple or
   yellow or white flowers that open in late afternoon; called
   also four-o'clock. See four-o'clock.

   Syn: common four-o'clock, marvel of Peru, Mirabilis jalapa,
        Mirabilis uniflora.
        [WordNet 1.5]