θυμός

So finally he gives up in despair: τέλος δὲ ἀθυμεῖ καὶ καταβαίνει τὸ ὄρος (= βαδίζει κατὰ τὸ ὄρος)
ἀθυμεῖ - he despairs.
Word-families make understanding new words, and therefore also remembering them, much easier:
ὁ θυμός, τοῦ θυμοῦ means soul, life; courage, spirit.....
we then get to the adjective ἄθυμος, ἄθυμον, downcast, discouraged, dejected
which in turn gives us the verb ἀθυμῶ [ἀθυμέω], I am disheartened, discouraged
and the noun ἡ ἀθυμία, τῆς ἀθυμίας, dejection, despair
We'll find many more words that have θυμός as their radical. A good word to remember.
    ἆρα ἀθυμεῖς πολλάκις while trying to learn Greek?
    ἆρα ἀθυμεῖς ῥᾳδίως when things get a little tough?
    ἆρα καὶ (also, even) ἀνὴρ ἀνδρεῖος ἀθυμεῖ;