If a site is listed on the DMoz open directory, Google will often use the title and description from the Open Directory Project (ODP) as the title and snippet for a search result instead of using the meta title and description entered in the head section of the site.

The "noodp" tag lets you opt out of the ODP title and description for the search title and snippet.  The snippet is implemented as follows:

<meta name="robots" content="noodp">

The tag also can be used as

<meta name="googlebot" content="noodp" />

if the problem is found to occur only with Google.