Anticipate enemies crossing river by middle of week (7)
I believe the answer is:
foresee
'anticipate' is the definition.
(synonyms)
'enemies crossing river by middle of week' is the wordplay.
'enemies' becomes 'foes' (a foe is an enemy or rival).
'crossing' is an insertion indicator (to cross can mean to go over or around).
'river' becomes 'r' (abbreviation for river).
'by' means one lot of letters go next to another.
'middle of' says to take the centre.
The central letters of 'week' are 'ee'.
'foes' placed around 'r' is 'fores'.
'fores'+'ee'='FORESEE'
(Other definitions for foresee that I've seen before include "To know beforehand" , "Be aware of beforehand" , "Expect" , "Prognosticate" , "divine" .)