ἀντιπαρέχειν
From LSJ
τοῦ δὲ πολέμου οἱ καιροὶ οὐ μενετοί → in war, opportunities won't wait | the chances of war will not wait (Thucydides 1.142.2)
Greek > English (Woodhouse Verbs Reversed)
(see also ἀντιπαρέχω): supply in return
Lexicon Thucydideum
vicissim praebere, to afford in turn, 6.21.1.