noun
A regularly-shaped slab of clay or other material, affixed to cover or decorate a surface, as in a roof-tile, glazed tile, stove tile, carpet tile, etc.
(computing) A rectangular graphic.
Any of various flat cuboid playing pieces used in certain games, such as dominoes, Scrabble, or mahjong.
(dated, informal) A stiff hat.
(Lego building) A Lego piece that is 1/3 the height of a brick, and is smooth without studs on top.
verb
(transitive) To cover with tiles.
(graphical user interface) To arrange in a regular pattern, with adjoining edges (applied to tile-like objects, graphics, windows in a computer interface).
(computing theory) To optimize (a loop in program code) by means of the tiling technique.
(Freemasonry) To seal a lodge against intrusions from unauthorised people.
verb
To protect from the intrusion of the uninitiated.