Prophesied start of future by one seer, strangely (8)
I believe the answer is:
foreseen
'prophesied' is the definition.
(thesaurus)
'start of future by one seer strangely' is the wordplay.
'start of' indicates taking the first letters.
'by' is a charade indicator (letters next to each other).
'strangely' indicates an anagram.
The first letter of 'future' is 'f'.
'one'+'seer'='oneseer'
'oneseer' is an anagram of 'oreseen'.
'f'+'oreseen'='FORESEEN'
(Other definitions for foreseen that I've seen before include "Envisaged" , "No surprise" , "Predicted" , "Anticipated" , "Expected" .)