This is the 11347th most frequent Portuguese word.
motivacional
"Motivacional" means "motivational," relating to the act of inspiring or encouraging motivation.
Here, 'motivacional' describes a characteristic of the speech aimed at inspiring and encouraging the audience.
O discurso dele foi extremamente motivacional e inspirou todos os presentes.
His speech was extremely motivational and inspired everyone present.
In this sentence, 'motivacional' qualifies 'books' as those that aim to motivate or inspire the reader.
Ela lê livros motivacionais para se sentir mais confiante e determinada.
She reads motivational books to feel more confident and determined.
This usage refers to a lecture designed to inspire and promote determination among its attendees.