Marvel? Marcel, I suspect (7)
I believe the answer is:
miracle
'marvel?' is the definition.
(I've seen this in another clue)
'marcel i suspect' is the wordplay.
'suspect' is an anagram indicator (a suspicious or unusual spelling).
'marcel'+'i'='marceli'
'marceli' is an anagram of 'MIRACLE'.
(Other definitions for miracle that I've seen before include "Event that appears to break the law of nature" , "Supernatural or wonderful event" , "Remarkable and welcome event" , "It's said to happen by the divine intervention" , "astonishing feat" .)