This is the 1346th most frequent Catalan word.
breu
Short; brief.
Here, 'breu' is used as an adjective to describe something that is concise in time or content, in this case, a speech.
El seu discurs va ser breu pero succint.
His speech was brief but succinct.
'Breu' in this sentence is used to qualify a chapter, implying it is small in length.
La novel·la té un capítol breu al principi.
The novel has a brief chapter at the beginning.
In this context, 'breu' means a short duration of time for the visit allowed.