θάλλω (thallō)

1. to bloom, abound, to be luxuriant , of fruit-trees, (Odyssey by Homer), etc.; often in participle perfect τεθηλώς, epic feminine τεθαλυῖα, as adjective, luxuriant, exuberant , (Odyssey by Homer); with accusative cognate, οὐ δένδρε᾽ ἔθαλλεν χῶρος the place grew no trees, θαλλούσης βίον ἐλαίας (Aeschulus Tragicus)
2. of other natural objects, τεθαλυῖα ἐέρση the fresh or copious dew, (Odyssey by Homer); τεθαλυῖα ἀλοιφῆι rich with fat, (Iliad by Homer); εἰλαπίνηι τεθαλυίηι at a sumptuous feast, (Iliad by Homer)
3. of men, to bloom, flourish , (Hesiod), etc.
4. in bad sense, to be active , νόσος ἀεὶ τέθηλε (Sophocles Tragicus); πήματα ἀεὶ θάλλοντα (Sophocles Tragicus) (ML)