noun
oo
OH-oh
noun
1
The Greek letter omega (Ω, ω), sometimes written this way to show its long "o" sound.
"The physics formula used oo to represent angular velocity."
2
Any of several now-extinct Hawaiian honeyeater-like birds of the genus Moho, prized historically for their yellow feathers.
"The last confirmed oo sighting was decades before the species was declared extinct."
How to Use Oo
Learner’s notesIn plain EnglishEither a way of writing the Greek letter omega, or an extinct Hawaiian bird once hunted for its feathers.
Word Forms
oos plural, oos plural
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Etymology
The bird sense comes from Hawaiian ʻōʻō, imitating the bird's call; the letter sense is simply a spelled-out way of writing the long "o" sound of omega.