This is the 9955th most frequent Spanish word.
buscaron
"They looked for"
Here, 'buscaron' is used as a past tense verb to indicate an action of searching for something (the book) that occurred in the past.
Ellos buscaron el libro que se había extraviado.
They searched for the book that had been lost.
In this sentence, 'buscaron' describes the action undertaken by the friends in the past to locate a suitable setting for their conversation.
Mis amigos buscaron un lugar tranquilo para conversar.
My friends looked for a quiet place to talk.
The word 'buscaron' here refers to their past action of evaluating options for their journey back home.