broadcast marathon; sequential broadcast
Refers to broadcasting multiple episodes of a radio or television series in one continuous block, often as a special event.
There will be a broadcast marathon of the popular drama at the end of the year.
You can watch all episodes of this anime in a sequential broadcast.
Compound of 一挙 (いっきょ, 'in one go') and 放送 (ほうそう, 'broadcast').