This is the 2679th most frequent Japanese word.
海鮮
Seafood.
Here, '海鮮' (seafood) is used as a descriptor for the type of cuisine.
私は海鮮料理が大好きです。
I love seafood dishes.
In this sentence, '海鮮' refers to the items of food sourced from the sea, typically fish or shellfish.
市場で新鮮な海鮮を購入しました。
I bought fresh seafood at the market.
The word '海鮮' is used more broadly here to convey a culinary specialty of the restaurant involving seafood.