The term likely predates the Rust implementation. SerDe is Serializer & Deserializer, which could be any framework or tool that allows the serialization and deserialization of data.
I first came across the concept in Apache Hive.
I first came across the concept when AWS Glue was messing up my CSVs on import
In case you weren't aware, Glue's metastore is an implementation of Apache Hive, so not too different from the person you're replying to.
I meant serialize / deserialize in the literal sense.