It's a struggle for an amphibian to get around (6)
I believe the answer is:
effort
'it's a struggle' is the definition.
(I've seen this in another clue)
'for an amphibian to get around' is the wordplay.
'an amphibian' becomes 'eft' (eft is a kind of amphibian).
'to get around' is an insertion indicator.
'for' placed inside 'eft' is 'EFFORT'.
(Other definitions for effort that I've seen before include "Vigorous attempt" , "Energy exerted to achieve something" , "Attempt - hard work" , "Try - labour - pains" , "Attempt, endeavour" .)