This is the 2473rd most frequent Spanish word.
acaso
Perhaps; maybe.
Expressing doubt or uncertainty.
Acaso piensas que tienes razón en esta disputa.
Perhaps you think you are right in this dispute.
Introducing a question with a suggestion of doubt.
¿Acaso viste quién tomó el libro?
Did you by any chance see who took the book?
Illustrating a hypothetical condition or possibility.