In Japanese, baku has several meanings. One of them is tapir, an animal. Another is "burst of laughter". In Japanese folklore, baku are supernatural beings resembling tapirs that devour dreams and nightmares.
Usage
See Special:Whatlinkshere/Etymology:Baku for a list of articles using this term.
This is an etymology page: a page detailing the origins of terminology used in the series in regards to real world culture and history.