Sentence:  These functions collide, and we can see in Figure 7-1 that the <code>debug()</code> function for SexyWidgets <WSD>clobbers</WSD> the developer′s <code>debug()</code> function. The last function declared with the same name in the same scope will silently <WSD>clobber</WSD> the earlier function definition. 
Meaning of the word marked with <WSD> tags:  To overwrite (data) or override (an assignment of a value), often unintentionally or unexpectedly.