What might offer illumination when in fix? (8)
I believe the answer is:
casement
'what might offer illumination' is the definition.
I can't tell whether this defines the answer.
'when in fix?' is the wordplay.
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
'in' means one lot of letters goes inside another.
'fix?' becomes 'cement' (cementing is a kind of fixing).
'as' placed inside 'cement' is 'CASEMENT'.
Can you help me to learn more?
(Other definitions for casement that I've seen before include "window frame" , "Irish Roger" , "Irish nationalist" , "Roger's window?" , "a man deemed to have betrayed England" .)