This is the 4573rd most frequent Portuguese word.
contendo
"Containing."
Here, 'contendo' is used in the present tense to describe the action of holding or including valuable information within the book.
O livro está contendo informações valiosas.
The book is containing valuable information.
In this sentence, 'contendo' indicates the act of restraining or controlling his anger as he arrived.
Ele veio até aqui contendo a sua raiva.
He came here containing his anger.
The word 'contendo' here refers to the act of managing or preventing the situation from escalating or worsening.