Definition of grayling:
(n) :
Any freshwater fish of the genus Thymallus or specifically Thymallus thymallus, of the salmon family, having a large dorsal fin.
(n) :
Thymallus arcticus (Arctic grayling)
(n) :
Other similar fish
(n) :
Salmo salar (Atlantic salmon)
(n) :
Prototroctes maraena (Australian grayling)
(n) :
Prototroctes oxyrhynchus (New Zealand grayling)