Forecast from pair ahead of decree (7)
I believe the answer is:
predict
'forecast' is the definition.
(synonyms)
'pair ahead of decree' is the wordplay.
'pair' becomes 'pr'.
'ahead of' says to put letters next to each other (I've seen this in other clues).
'decree' becomes 'edict' (synonyms).
'pr'+'edict'='PREDICT'
'from' is the link.
(Other definitions for predict that I've seen before include "Estimate consequence of" , "Anticipate" , "Foresee" , "Foretell, prophesy" , "Guess (the future)" .)