Live in a mad state of desire (6)
I believe the answer is:
reside
'live in' is the definition.
(I've seen this before)
'of desire' is the wordplay.
'of' indicates an anagram (the answer comes from or 'of' the letters).
'desire' anagrammed gives 'RESIDE'.
'a mad state' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for reside that I've seen before include "Dwell, be present (in)" , "Live in permanently" , "Desire (anag) - to live" , "'Live, dwell (6)'" , "Dwell in desire" .)