Wiktionary
n. A plane used for final flattening out of wooden surfaces.
WordNet
n. a long carpenter's plane used to shape the edges of boards so they will fit together [syn: jointer, jointing plane, long plane]
Wikipedia
The jointer plane (also known as the try plane or trying plane) is a type of hand plane used primarily to straighten the edges of boards in the operation known as jointing. A jointer plane may also be used to flatten the face of a board. Its long length is designed to 'ride over' the undulations of an uneven surface, skimming off the peaks, gradually creating a flat surface. In thicknessing or preparing rough stock, the jointer plane is usually preceded by the fore plane or jack plane and followed by the smoothing plane.
Jointer planes are typically long.