noun
first collection; first volume; first series
Used for the first installment of a multi-part publication, such as a book series, anthology, or collected works.
この作家の第一集は短編集です。
This author's first collection is a short story anthology.
全集の第一集が来月発売されます。
The first volume of the complete works will be released next month.
Compound of 第一 (first) + 集 (collection/volume). The reading だいいっしゅう reflects the gemination of いち to いっ before しゅう.