Your peeves are welcome here! Now I wonder if there’s a reddit for that!
Sometimes your friends can make unhelpful comments. So I thought about this:
While the term ‘fish’ is redundant, you should realise that English is full of such redundancy. Pointing out such ‘incorrect’ usage isn’t particularly helpful, esp. when it is hypercorrection.
Some pleonastic phrases are part of a language’s idiom, like tuna fish, chain mail and safe haven in American English. They are so common that their use is unremarkable and often even unnoticeable for native speakers, although in many cases the redundancy can be dropped with no loss of meaning.
For example, most English speakers would agree that “tuna fish” is redundant because tuna is a kind of fish. However, given the knowledge that “tuna” can also refer to a kind of edible prickly pear,[20] the “fish” in “tuna fish” can be seen as non-pleonastic, but rather a disambiguator between the fish and the prickly pear.
I’m leaving this rabbit hole now…