serializer; parallel-to-serial converter
Technical computing term for a device or circuit that converts parallel data into serial form. 'Dynamicizer' is an older or less common synonym.
A serializer is a circuit that converts parallel data into serial data.
The opposite device: a deserializer that converts serial data back to parallel form.
Compound of 並 (parallel), 直列 (serial), and 変換器 (converter). A straightforward technical term with no known historical derivation beyond its components.