I believe this refers to the size or width of the tenon. Making it almost the the size of the board it is in gives more surface area for glue.
Expansion joints. Butt,lap,half-housed,mortise/tenon and mitre joints to name some common ones.
tenon
A mortise and tenon joint connects two pieces of wood or other material. Woodworkers around the world have used it for thousands of years to join pieces of wood, mainly when the adjoining pieces connect at right angels. In its most basic form. a mortise and tenon joint is both simple and strong.
to fill the groove cut for the panel
Expansion joints. Butt,lap,half-housed,mortise/tenon and mitre joints to name some common ones.
The partner of a mortise is a tenon. A mortise is a cavity or hole cut into a piece of wood or other material, while a tenon is a projecting piece of wood or other materials that is designed to fit into the mortise, creating a joint. Together, a mortise and tenon form a strong and stable connection in woodworking.
Butt joint Mortise and tenon Dovetail Corner joint finger joint
Tenon (a woodworking joint)
Mortise and tenons are used by woodworkers to join pieces of wood. the basic mortise and tenon comprises two components: the mortise hole and the tenon tongue.
Tenon (a woodworking joint)
MORTICE and TENNON
The joints on door-jamb liners are traditionally housed.Joints on doors,sashes and gates are traditionally tenon-mortise.
tenon
Mortise and tenon joint. Gravity
A Mortise is usually a piece cut out and the insert is called a tenon...these two pieces make a joint.