What does quid aī̆s mean in Latin?

quid aī̆s, a phrase, means “eh?, what?, what did you say?, what are you saying?, you don't say!; tell me, what do you say?”.

How do you pronounce quid aī̆s?

In classical Latin, [ˈkʷɪ.da.iːs]; in ecclesiastical (church) Latin, [ˈkʷid ˈaː.is].

phrase

Classical[ˈkʷɪ.da.iːs]Ecclesiastical[ˈkʷid ˈaː.is]

colloquialeh?, what?, what did you say?, what are you saying?, you don't say!
colloquialtell me, what do you say?
(after talking to himself) Sed quid aīs, quō inde īstī porrō?But tell me, where did you go next?c. 195 BCE, Plautus, Trinummus 4.2.99
THAIS: Ita mē dī ament honestust.THAIS: God bless me he's handsome. PARMENO: What do you say, Gnatho? Do you see anything to find fault with? And what say you, Thraso? They're speechless, which is praise enough. Test him on literature, athletics, music; I'll warrant him well skilled in everything a gentleman should know.161 BCE, Publius Terentius Afer, Eunuchus 3.2

From quid (“what”) + aī̆s (“you say”), the 2nd person sg. of aiō (“to say”).