(n.)
ʹænɪʃ [anniversary + ish] the issue of a fanzine published on an anniversary of its first appearance.
1950 A. Rapp Spacewarp (Jan.) № 2: March brings us SPACEWARP's Third Ann[-]Ish.
1952 J. Wellons Thrilling Wonder Stories (letter) (Dec.) № 140/1: But for those who do like the Cap, may I second Joe Kinnon's motion for an Annish for Futurians.
1960 J. Speer Novus Ordo Fandorum Fancestral Voices (2004) № 190: Begin, neo, to plan they little subzine, though it never see an annish.
1966 L. Carter Handy Phrase-Book in Fannish If (Oct.) № 66/2: If your fanzine lasts a year (many don't) you put out a particularly large Anniversary Issue called "the Annish."