This is the 687th most frequent Portuguese word.
altura
"Altura" in Portuguese means "height" or "altitude."
This sentence uses 'altura' to refer to the physical dimension measuring how tall the building is.
A altura do prédio é impressionante.
The height of the building is impressive.
Here, 'altura' is figuratively used to denote a specific point in time.
Naquela altura, ninguém sabia o que fazer.
At that point, no one knew what to do.
In this case, 'altura' indicates the adjustable vertical position of the chair.