Animal sailor attached to a line (6)
I believe the answer is:
jackal
'animal' is the definition.
(I have seen 'Doglike animal ' mean 'jackal' so perhaps 'animal' could also mean 'jackal')
'sailor attached to a line' is the wordplay.
'sailor' becomes 'jack' (I've seen this before).
'attached to' means one lot of letters go next to another.
'line' becomes 'l'.
'jack'+'a'+'l'='JACKAL'
(Other definitions for jackal that I've seen before include "Dog-like carnivore" , "African wild dog" , "Frederick Forsythe novel: ''Day of the ......''" , "Flunkey; dog-like omnivore" , "Nocturnal dog-like predator" .)