However, taking that as understood, let us ask how a word can have a meaning. Some words can be defined in terms of other words: "square" for example means "four-sided equilateral equiangular plañe figure." And most of the terms in that definition can also be defined. But definitions can't be the basis of meaning for all words, or we'd go fore ver in a circle. Eventually we must get to some words which have meaning directly.
[Thomas Nagel, What does it all mean, p.39]
I don;t know the meaning of "taking that as understood". Could you help me please?