This is the 14312th most frequent Russian word.
отданное
"Отданное" means "given" or "delivered."
Here, 'отданное' is used as a participle meaning 'dedicated' and is describing 'время,' indicating time allocated to a project.
Это отданное тому проекту время окупилось.
The time dedicated to that project has paid off.
Here, 'отданные' is an adjective derived from the verb 'отдать,' describing 'книги,' indicating that the books were presented or given.
Спасибо за отданные мне книги.
Thank you for the books given to me.
In this case, 'отданное' describes 'внимание,' indicating focus or care provided to a person.