This is the 359th most frequent Catalan word.
líder
Leader.
Here, "líder" is used as a noun to mean the person who leads or is in charge of a group.
El líder de l'equip va motivar els jugadors abans del partit.
The team leader inspired the players before the game.
Here, the word "líder" is used as an adjective to describe an entity (the project) that is at the forefront or excels in a certain field.
Aquest projecte és líder en innovació tecnològica.
This project is leading in technological innovation.
In this sentence, "líder" is again a noun, emphasizing the person's ability to stand out and take charge in activities.