Where can I get Google Search Result API

Hey Hi I am looking for a solution in which I could provide users visited my site an option to find out monthly search volume for a particular keyword. There must be an API which Google might be providing. Because I have seen plenty website they provide such option. I want to know about such

Can I use Adwords API in my website to show search volume for a particular keyword

Hi I am looking for an API to access search volume for a particular. I am wondering can I use Adwords API to provide a feature in my website where people can search search volume for a particular keyword. If there is any other api from Google is available, then please let me know. Thanks. --