The notion of definition or defining characteristics (Skt. lakṣaṇa; Tib. མཚན་ཉིད་, tsennyi, Wyl. mtshan nyid) is a very important one in Buddhist philosophy, so much so that the sutra vehicle is often known as the vehicle of characteristics. A correct and useful definition must avoid the three faults of being too narrow, too broad or impossible.
In Pramana, definition (mtshan nyid) is usually discussed in terms of the triad of definition (mtshan nyid), name (lakṣya; mtshon bya) and basis of definition (mtshan gzhi).
For example, in the case of a vase:
- the definition is something like "narrow-necked, bulbous object capable of holding water"
- the name (or definiendum) is "vase"
- and the basis of definition (or illustration) is the particular instance, such as the green vase on your table.