Difficult enough after losing answer in guide (7)
I believe the answer is:
complex
'difficult' is the definition.
(I've seen this before)
'enough after losing answer in guide' is the wordplay.
'enough' becomes 'ample' (I've seen this before).
'after losing' suggests deleting specific letters.
'answer' becomes 'a' (abbreviation eg in Q and A).
'in' means one lot of letters goes inside another.
'guide' becomes 'cox' (person who steers a rowing boat).
'ample' with 'a' removed is 'mple'.
'mple' inserted inside 'cox' is 'COMPLEX'.
(Other definitions for complex that I've seen before include "Complicated in structure" , "with real and imaginary parts" , "Consisting of interconnected parts" , "Hard to understand or of many parts" , "Obsession - not simple" .)