How do I exclude a specific field value from search results?

[shiroyasha_]

I'm trying to exclude a specific value from my search result, what I'm currently getting is the list of top hosts using this query

sourcetype=akamaisiem | timechart  count by httpMessage.host

From my query I'm getting all the hostnames, how do I exclude a specific value from the results?

[renjith_nair]

@shiroyasha_ ,

You can exclude the host before the timechart

 sourcetype=akamaisiem 'httpMessage.host' !="unwanted host" | timechart  count by httpMessage.host