Waa is likely misspelled.
Waa has no English definition.
As a noun yaa
is the letter ي in the Arabic script.
yaa
English
Noun
(
en noun)
The letter in the Arabic script.
Usage notes
* Some Arabic-based languages use variations of the letter, e.g. Persian uses (ye).
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waa
English
(onomatopoeia)
Interjection
(
en interjection)
The sound of a baby crying (often written twice: "Waa! Waa!").