brevetoxin
nounMedical Definition of brevetoxin
: any of several neurotoxic substances that are produced by a dinoflagellate (especially Karenia brevis synonym Gymnodinium breve) found in red tides, that may cause massive fish die-offs and sicken or kill marine mammals and birds, and that in humans may cause respiratory symptoms (such as coughing or shortness of breath) when inhaled and neurotoxic shellfish poisoning when ingested