2. Noun. (archaic) A seal (marine mammal), or a similar design in heraldry. ¹
3. Noun. dogfish ¹
4. Noun. (uncommon) An omen of bad luck. ¹
5. Noun. (uncommon) A white-topped wave in an estuary. ¹
¹ Source: wiktionary.com
Definition of Seadog
1. a fogbow [n -S] - See also: fogbow