Source : Webster's Revised Unabridged Dictionary (1913)

Glair \Glair\, n. [F. glaire, glaire d'?uf, the glair of an egg,
   prob. fr. L. clarus clear, bright. See {Clear}, a.]
   1. The white of egg. It is used as a size or a glaze in
      bookbinding, for pastry, etc.

   2. Any viscous, transparent substance, resembling the white
      of an egg.

   3. A broadsword fixed on a pike; a kind of halberd.

Glair \Glair\, v. t. [imp. & p. p. {Glaired}; p. pr. & vb. n.
   {Glairing}.]
   To smear with the white of an egg.