From Wiktionary, the free dictionary
From ఏ (ē) + అవి (avi).
ఏవి • (ēvi) (singular ఏది)
- (interrogative) which
- నీళ్లు ఏవి? ― nīḷlu ēvi? ― Where is the water?
"ఏవి" in Charles Philip Brown (1903) A Telugu-English dictionary, Madras: Promoting Christian Knowledge, page 202