1) Fish genus 2) Genus esox 3) Genus of freshwater fish 4) Pickerel genus 5) Pickerel or pike 
Esox is a genus of freshwater fish, the only living genus in the family Esocidae—the esocids which were endemic to North America, Europe and Eurasia during the Paleogene through present. The species of this genus are known as pike and pickerel, and in heraldry a fish of the genus is usually called a lucy (English heraldry) or a ged (Scottish her...
• (n.) A genus of fresh-water fishes, including pike and pickerel.
fish genus that includes the popular game fishes known as pike, pickerel, and muskellunge (qq.v.).
E'sox noun [ Latin , a kind of pike.] (Zoology) A genus of fresh-water fishes, including pike and pickerel. 
[n] - type and only genus of the family Esocidae
genus Esox noun type and only genus of the family Esocidae