This is the 9486th most frequent Portuguese word.
concentre
"Concentre" in Portuguese means "focus" or "concentrate."
Concentre is an imperative verb here, instructing the listener to focus.
Por favor, concentre-se no trabalho agora.
Please, focus on your work now.
Concentre is in the subjunctive mood, indicating a suggestion or request for focusing.
Ela pediu que ele se concentre nos estudos para o exame.
She asked him to concentrate on his studies for the exam.
Concentre here is part of a subjunctive clause expressing a hope about focusing.