How do you spell Glair

Available Definitions:
1)  a. - The white of egg. It is used as a size or a glaze in bookbinding, for pastry, etc.
2)  a. - Any viscous, transparent substance, resembling the white of an egg.
3)  a. - A broadsword fixed on a pike; a kind of halberd.
4)  v. t. - To smear with the white of an egg.