Sentence:  In this chapter, we present some example applications of the Gaussian <WSD>quadrature</WSD> methods discussed in the previous chapters....Figure 4.1 shows the accuracy of the polynomial Gaussian <WSD>quadratures</WSD> used to evaluate the first two integrals as a function of "N". 
Meaning of the word marked with <WSD> tags:  The calculation of a definite integral by numerical means.