J.R.R. Tolkien called the Ents the Onodrim in the languages of Middle-earth.
Ents are tree-like shepherds who protect forests and other growing things. Their name comes from Tolkien’s invented languages, while “Onodrim” is a plural form associated with the Sindarin word for these beings. The character Treebeard is the most prominent Ent in The Lord of the Rings.
The Ents’ most important action in the story is their assault on Isengard. Angered by Saruman’s destruction of trees, Treebeard and the other Ents march against the fortress and help bring down its defenses. Their long deliberation reflects their slow, ancient way of life.
Ents are sometimes confused with Huorns, related tree-beings that are more mysterious and less openly person-like. Tolkien also drew on the old English word “ent,” meaning a giant or powerful being. In Middle-earth, however, the term specifically evokes the sentient tree shepherds.