The Collaborative International Dictionary of English v.0.48:

Solitaire \Sol`i*taire"\, n. [F. See Solitary.]
   1. A person who lives in solitude; a recluse; a hermit.
      --Pope.
      [1913 Webster]

   2. A single diamond in a setting; also, sometimes, a precious
      stone of any kind set alone.
      [1913 Webster]

            Diamond solitaires blazing on his breast and wrists.
                                                  --Mrs. R. H.
                                                  Davis.
      [1913 Webster]

   3. A game which one person can play alone; -- applied to many
      games of cards, etc.; also, to a game played on a board
      with pegs or balls, in which the object is, beginning with
      all the places filled except one, to remove all but one of
      the pieces by "jumping," as in draughts.
      [1913 Webster]

   4. (Zool.)
      (a) A large extinct bird (Pezophaps solitaria) which
          formerly inhabited the islands of Mauritius and
          Rodrigeuz. It was larger and taller than the wild
          turkey. Its wings were too small for flight. Called
          also solitary.
      (b) Any species of American thrushlike birds of the genus
          Myadestes. They are noted their sweet songs and
          retiring habits. Called also fly-catching thrush. A
          West Indian species (Myadestes sibilans) is called
          the invisible bird.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Invisible \In*vis"i*ble\, a. [F. invisible, L. invisibilis. See
   In- not, and Visible.]
   1. Incapable of being seen; not perceptible by vision; not
      visible. Specifically:
      (a) Not visible due to an inherent property, such as lack
          of color; as, the invisible air; invisible ink;
      (b) hidden from view; out of sight;
      (c) Not perceptible due to lack of light;
      (d) Too small or too distant to be perceived; as, people
          on the ground invisible at cruising altitude.
          [1913 Webster +PJC]

                To us invisible, or dimly seen
                In these thy lowest works.        --Milton.
          [1913 Webster]

   2. Hidden from the public; as, invisible transactions.
      [PJC]

   3. imperceptible to the mind; as, differences invisible to
      most observers.
      [PJC]

   Invisible bird (Zool.), a small, shy singing bird
      (Myadestes sibilons), of St. Vincent Islands.

   Invisible green, a very dark shade of green, approaching to
      black, and liable to be mistaken for it.
      [1913 Webster]