Title tag

The text displayed in the blue bar at the very top of the browser window, above "Back," "Forward," "Refresh," "Print," etc. Although inconspicuous to the user, the title tag is the most important bit of text on a web page as far as the search engines are concerned. Search engines not only assign the words in the title tag more weight, they also typically display the title tag in the search results, making the title tag an important potential call-to-action as well. Thus, the wording of each page's title tag should be thought through carefully. Also see "keyword prominence."

Spider Trap

A spider trap refers to either a continuous loop where spiders are requesting pages and the server is requesting data to render the page or an intentional scheme designed to identify (and "ban") spiders that do not respect robots.txt.

NoFollow

A tag used to stop search engines parsing on PageRank to sites linked to the host site

crawls

Fresh Crawl
Utilizes FreshBot to review already indexed pages and any pages where the content has been

updated. FreshBot
A sister to GoogleBot, this spider crawls highly ranked sites on a very frequent basis.

Deep Crawl

Deep Crawl
Once a month, Googlebot will crawl all of the links it has listed in it's database on your site. This is known as the Deep Crawl.

PFI

Abbreviation for Pay For Inclusion. Many search engines offer a PFI program to assure frequent spidering / indexing of a site (or page). PFI does not guarantee that a site will be ranked highly (or at all) for a given search term. It just offers webmasters the opportunity to quickly incorporate changes to a site into a search engine's index. This can be useful for experimenting with tweaking a site and judging the resultant effects on the rankings

Outbound links

links that direct "off-site" to another website

Dead Link

Dead links should always be avoided. In the first place they make your website look sloppy to your visitors and search engines also don’t like them for determining your content and PR. A dead link is basically a hyperlink pointing to a non-existent URL. There are several tools on the internet that can automatically detect your websites dead link. Also, your logs can tell you what pages were not found, so you can determine which pages link to them.
A simple way to solve the problem is to create custom 404 pages that tell users the page could not be found, but does provide links to other pages on your website. This way users will not immediately hit the back button and they’ll stay on your site.
You could do this by directing all non existing pages to your some page using code in a htaccess file: