(Internet) To label (a message) with a hashtag.
The definition of a hashtag is the pound mark used after a word in a Twitter post or “tweet” to show that you’re commenting on a specific topic.
An example of a hashtag is to write about the president on Twitter and end your tweet with #Obama.
A word or phrase preceded by the symbol (#), used in social networking to identify the subject of a conversation and to facilitate searches for that subject.
A searchable keyword or sequence of characters prefixed with the pound sign (#), included in a tweet or other electronic communication and indicating the subject matter.
A topic identifier in a tweet or other social network message that is indexed by the service so that all the user postings with that hashtag can be searched and read. The hashtag is the name of the topic with a number sign (#) prefix, also called a hash mark.Hashtags are created for anything and everything, including people, businesses, organizations, sports teams, political parties, hobbies, events and philosophies, as well as rants and raves. For example, athletes might be interested in #triathlon or #ironman. See hash, tag, Twitter and bashtagging.