Unclear when I had turned into drive (10)
I believe the answer is:
indistinct
'unclear' is the definition.
(synonyms)
'i had turned into drive' is the wordplay.
'i had' becomes 'i'd' (contraction).
'turned' says the letters should be written backwards.
'into' means one lot of letters goes inside another.
'drive' becomes 'instinct' (I can't justify this - if you can you should give a lot more credence to this answer).
'id' backwards is 'di'.
'di' inserted within 'instinct' is 'INDISTINCT'.
'when' is the link.
Can you help me to learn more?
(Other definitions for indistinct that I've seen before include "Blurred" , "Not clearly defined" , "Obscure" .)