noun
final issue; last issue (of a suspended publication)
Refers specifically to the last issue of a magazine, newspaper, or periodical that has ceased or suspended publication. Not used for the final issue of a regularly ending series.
その雑誌は休刊号を最後に姿を消した。
The magazine disappeared after its final issue.
休刊号には編集長の挨拶が載っていた。
The final issue carried a message from the editor-in-chief.
廃刊 means discontinuation of a publication; 休刊号 is the issue marking that suspension.
Compound of 休刊 (suspension of publication) and 号 (issue, number).