The Avestan word aēuua
Word aēuua
Meaning one

Other words that might be of interest
ašta ‘eight, 8’, xšuuaš ‘six, 6’, θritiia- ‘third’, paoiriia- ‘first’, paṇca ‘five, 5’, bitiia- ‘second’, hapta ‘seven, 7’, caθβarasca ‘four’