Heavy alligator, disorientated at being released (7)
I believe the answer is:
gorilla
'heavy' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for gorilla that I've seen before include "Largest living primate" , "thug" , "Ape - aggressive muscleman" , "huge beast" , "African great ape" .)