Editing WordNet (section)

== Knowledge structure ==
Both nouns and verbs are organized into hierarchies, defined by [[hypernym]] or ''[[is-a|IS A]]'' relationships. For instance, one sense of the word ''dog'' is found following hypernym hierarchy; the words at the same level represent synset members. Each set of synonyms has a unique index.
{{tree list}}
* {{Tree list/final branch}}dog, domestic dog, Canis familiaris
** {{Tree list/final branch}}canine, canid
*** {{Tree list/final branch}}carnivore
**** {{Tree list/final branch}}placental, placental mammal, eutherian, eutherian mammal
***** {{Tree list/final branch}}mammal
****** {{Tree list/final branch}}vertebrate, craniate
******* {{Tree list/final branch}}chordate
******** {{Tree list/final branch}}animal, animate being, beast, brute, creature, fauna
********* {{Tree list/final branch}}...
{{tree list/end}}
At the top level, these hierarchies are organized into 25 beginner "trees" for nouns and 15 for verbs (called ''lexicographic files'' at a maintenance level). All are linked to a unique beginner synset, "entity".
Noun hierarchies are far deeper than verb hierarchies.

Adjectives are not organized into hierarchical trees. Instead, two "central" antonyms such as "hot" and "cold" form binary poles, while 'satellite' synonyms such as "steaming" and "chilly" connect to their respective poles via a "similarity" relations. The adjectives can be visualized in this way as "dumbbells" rather than as "trees".