This is the 8394th most frequent Spanish word.
pío
The word "pío" in Spanish means "chirp" (the sound made by birds).
The word 'pío' is used idiomatically to refer to any faint or minor sound, analogous to 'a word' in English in expressions of silence.
No he dicho ni pío en toda la reunión.
I haven't said a word during the entire meeting.
Here, 'pío' refers to the chirping or peeping sound made by birds, reflecting its origin as a mimetic word.
Por la mañana escuché el pío de los pájaros.
In the morning I heard the chirping of the birds.
In this colloquial usage, 'pío' signifies any small amount of something, emphasizing the absolute lack thereof.