From Wiktionary, the free dictionary
Explanatory compound from Hai (“shark”) + Fisch (“fish”).
Haifisch m (strong, genitive Haifisches or Haifischs, plural Haifische)
- (chiefly informal) Synonym of Hai (“shark”)
Declension of Haifisch [masculine, strong]
- “Haifisch” in Duden online
- “Haifisch” in Digitales Wörterbuch der deutschen Sprache