From 穴(あな) (ana) + 釣(つ)り (tsuri, 連(れん)用(よう)形(けい) (ren'yōkei, “stem or continuative form”) of the verb 釣(つ)る (tsuru)). The tsuri changes to zuri as an instance of rendaku (連濁).
あなづり • (anazuri) ←あなづり (anaduri)?