This word is from the Spanish word bañera (meaning: bath tub).
The word banyera has come to have an extended meaning in Tagalog. Other containers that are not necessarily used for bathing or washing laundry can also be referred to as banyera. For instance, in the title of Filipino television show Prinsesa ng Banyera, the banyera refers to a fish bucket.
tub for bathing
isdang banyera ang benta
fish sold by the bucket
loads of fish
It usually refers to a container that is relatively flat and wide.