In another thread, "salt cellars" were mentioned. I did not realize that this is a tautology.

Furthermore, those who were wealthy enough to have saltcellars [small
dishes used for holding and dispensing salt] just as recently as 300 years
ago were deemed to have "status," and they were looked highly upon and
esteemed by their "underlings"! Contrary to frequent belief, a saltcellar is
not a location for storing salt but rather it is merely a "compound
redundancy," that is, tautology, for the word "salt":

Cellar (as in saltcellar) comes from the Anglo-Norman saler [and later
seler], another word for saltcellar, a word derived from the Latin sal and
the corresponding verb, salere, to add salt to.