The same one in choppy lake (5)
I believe the answer is:
alike
'the same' is the definition.
(I've seen this in another clue)
'one in choppy lake' is the wordplay.
'one' becomes 'i' (Roman numeral).
'in' indicates putting letters inside.
'choppy' indicates an anagram (choppy implies disruption).
'lake' anagrammed gives 'alke'.
'i' going within 'alke' is 'ALIKE'.
(Other definitions for alike that I've seen before include "Share and share . . . . . - even Stephen" , "twins, perhaps" , "Comparable or similar" , "In a similar way" , "uniform" .)