This is the 614th most frequent Greek word.
επίθεσης
"Επίθεσης" means "attack" or "assault" in English.
In this sentence, 'επίθεσης' is the genitive singular form of the noun 'επίθεση', meaning 'attack'. It denotes possession or association (the strategy of the attack).
Η στρατηγική της επίθεσης ήταν καλά σχεδιασμένη.
The strategy of the attack was well planned.
Here, 'επίθεσης' is the genitive singular form of 'επίθεση'. It specifies the kind or type of act being referred to ('an act of assault').
Κατηγορήθηκε για τη συμμετοχή του σε μια πράξη επίθεσης.
He was accused of his involvement in an act of assault.
In this context, 'επίθεσης' is the same genitive form, showing relation to 'threat', as in the 'threat of attack'.