Since the OP indicated in his comments that he was only interested in the "/search directory", my answer below is in regards to disallowing just a "search" directory:
The following is a directive for robots not to crawl something named "search" located in the root directory, conventionally considered to be a file because it lacks a trailing forward slash:
Disallow: /search
According to the following Google Webmaster Tools help doc below, directory names should be proceeded and followed by a forward slash /, as also specified in the other following reference sources:
Google Webmaster Tools - Block or remove pages using a robots.txt file
To block a directory and everything in it, follow the directory name with a forward slash.
Disallow: /junk-directory/
Robotstxt.org - What to put in it
User-agent: *
Disallow: /cgi-bin/
Disallow: /tmp/
Disallow: /~joe/
In this example, three directories are excluded.
Wikipedia - Robots exclusion standard
This example tells all robots not to enter three directories:
User-agent: *
Disallow: /cgi-bin/
Disallow: /tmp/
Disallow: /junk/
So according to Google (as copied above), the following would disallow bots with the user-agent Mediapartners-Google from crawling the "search" directory located in the the root directory, but allow all other directories to be crawled:
User-agent: Mediapartners-Google
Disallow: /search/
Allow: /