Gateway Page (doorway page or a bridge page)
A web page designed to attract traffic from a search engine and then redirect it to another site or page. A doorway page is not exactly the same as cloaking but the effect is the same - i.e. users and search engines are served different content.

Geo-Targeting 
Advertising that is distributed based on geographic location. Online advertising allows for targeting of countries, states, cities and suburbs. 

Gizmo (gadget, widget)
Small applications used on web pages to provide specific functions such as a hit counter or IP address display. Gizmos can make good link bait.

Grey Hat SEO
SEO using both Black Hat and White Hat techniques.

Google
Google is the world's number one search engine with a 50.8% market share.
80% of searchers use Google.

Google AdSense
Paid ads webmasters may place on their websites

Google Analytics 
Google Analytics is a free web analytics tool offering detailed visitor statistics. The tool can be used to track all the usual site activities: visits, page views, pages per visit, bounce rates and average time on site etc.

Google Bombing 
Google Bombing is when a group of sites such as blogs join forces to link to an unflattering page about a company such that this page rises to the top of the search results in Google.

Google Bowling
Google Bowling is a black hat SEO technique used to knock competitors down or out of search engine results by pointing hundreds of low trust/low quality links at their website. The result of this sabotage can cause the competitor’s site to be banned or penalized by Google.

Googlebot 
Googlebot is a search bot (spider) used by Google. It collects documents from the web to build a searchable index for the Google search engine.

Google Dance
Google used to do a major algorithm update every few months. When it happened, the search engine results would fluctuate and site positions would change noticeably.

Google Juice
Internet slang referring to the substance (trust, authority, pagerank) from sites via their hyperlinks. Pages with lots of links pointing to them have more 'Google Juice'.

Google Sitelinks
On some search results where Google thinks one result is far more relevant than other results (like navigational or brand related searches) they may list numerous deep links to that site at the top of the search results.

Google's Supplemental Index
The primary measure of a pages importance is the number and quality of links pointing to that page. Pages in the Supplemental Index (a secondary index) can still rank in search results, but it will depend on the number of pages in the main index relevant to the search.

Google XML Sitemap 
Google Sitemaps are XML files that list the URLs available on a site. The aim is to help site owners notify search engines about the URLs on a website that are available for indexing.