What does Hassan mean?
From Arabic حسن (ḥasan) 'handsome, beautiful, good', from the root ḥ-s-n which also gives husn ('beauty'). The sense spans moral goodness and physical beauty.
What does Yahya mean?
The Arabic name of the prophet John the Baptist, Yahya. Traditionally associated with the root h-y-y (ح-ي-ي, 'to live'), read as 'he lives' or 'shall live', although as a prophet's name its ultimate origin is debated and linked to the Hebrew Yohanan. Hedged accordingly.