Webster's Revised Unabridged Dictionary · 1913

Glair

Glair , noun

[French glaire, glaire d'{not transcribed}uf, the glair of an egg, prob. from Latin 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 , transitive verb

To smear with the white of an egg.