Sentence:  We devote a chapter to the binomial distribution not only because it is a mathematical model for an enormous variety of real life phenomena , but also because it has important properties that recur in <WSD>many</WSD> other probability models . 
Meaning of the word marked with <WSD> tags:  a quantifier that can be used with count nouns and is often preceded by `as' or `too' or `so' or `that'; amounting to a large but indefinite number