This is the 4722nd most frequent Portuguese word.
eixo
Axis.
The word 'eixo' refers to the mechanical axle of the wheel in this context.
O eixo da roda está quebrado.
The axle of the wheel is broken.
Here, 'eixo' is used metaphorically to mean the central idea or focus of the discussion.
O eixo da discussão foi a educação das crianças.
The focus of the discussion was children's education.
In this sentence, 'eixo' represents the Earth's axis in a geographical sense.