What Do #FF, #TBT, #GFF, FOH, RLRT And Other Twitter & Instagram Hashtags & Terms Mean?

Twitter and Instagram have taken the world by storm, but they have their own language that many users, especially new ones, have a hard time understanding.

This glossary/dictionary will teach you the meanings behind key hashtags, abbreviations and slang terms like #FF, #TBT, #Icant, #Dead, SMH, FOH, #YOLO, CTFU and more. Many of them appear in both hashtag and written format, and they are all subject to the interpretation of the particular user, so don't take any of them as gospel.

And please let us know in the comments if there are any others we should add to this list, or if you feel that any of these definitions are incorrect. Enjoy!

#FF - This hashtag mostly shows up on Fridays, which should give you a good indication of what one of the Fs means. The other stands for Follow, and the two combine to make the phrase "Follow Friday." Follow Friday is essentially a Twitter holiday with the aim of getting people to follow one another. If you want someone to follow a musician, politician, friend or anyone else you think is interesting or should have more followers, simply tweet out a message listing their username (as in @username) along with the #FF hashtag. This is usually done in list form, with users tweeting a list of usernames along with #FF, so that people who trust their judgment can add a bunch of interesting accounts to their feeds.

#TBT - (Throwback Thursday) This is another "holiday" Twitter and Instagram hashtag, which shows up every Thursday on both sites. The impetus behind this one is that it is an opportunity for people to share photos and info that is a "throwback" to an earlier time. For instance, on Instagram, posting a picture of yourself as a child or when you were in school, or on Twitter telling a short quip about something in your past. This is a fun way for people to learn a little bit more about each other, and to see the funny or interesting past that each of us have, but many of our followers and friends don't know about.

#ICant, #Cryin #ImCrying and #Dead - These hashtags, and similar variations of them, are all a little bit misleading, but once you get one you can pretty much understand them all. Basically, when someone posts #ImDead, #Crying, #ICant or another similar hashtag, it means that something is hilarious, or very shocking. For instance, tweeting "Watch this video of this standup comedian's new bit #DEAD #ICant," would indicate that the video linked to or being commented on is so funny that the person is "dead" and "can't" go on living - meaning it's insanely funny. A little weird, but you get the point. It can also be used as a short-hand response to a funny or shocking image on Instagram.

I'm Out or #ImOut - This is basically a way of relaying the fact that a user thinks something is so insane, ridiculous or offensive that the person is done using Twitter or Instagram for the day. Obviously, this can be a literal signing off of the site, or just a way of saying that the thing in question has the person questioning his or her use of that social media site, though they may continue to stay logged in and engaging with the site.

SMH - This one is a carryover from the world of text-messaging, and it stands for "Shaking My Head." Basically, it means that the user who posts it is shaking his or her head either in disgust, shame, shock or some other form of reaction to the content it is referencing.

LMAO, LMFAO - This one also comes from the text-messaging and instant-messaging world, and it means either "Laughing My A-- Off," or "Laughing My F---ing A-- Off." Clearly it just means something is funny.

LOL, Lls - These both mean "Laugh Out Loud," one of the most ubiquitous of all such abbreviations, and they both indicate that the user who posts it thinks something is funny.

#YOLO - This is an abbreviation for "You Only Live Once." It can be interpreted in a number of ways, but most often indicates an activity that shows someone is living on the edge, either literally or sarcastically.

FOH, GTFO - These stand for "F--- Outta Here" and "Get The F--- Out." They both are terms used to dismiss whatever is being referenced.

HT or H/T - These both mean "hat tip," and are generally used to express endorsement or admiration of the content or user being referenced.

OH or RLRT - These stand for "overheard" or "Real-Life Retweet" and are used to reference something that a user has overheard in their real life. They are generally used in reference to shocking, odd or funny snippets of overheard conversations.

DM - (Direct Message) This one is a little bit more complicated, so we will let the official Twitter glossary break it down for you as follows: "Also called a DM and most recently called simply a "message," these Tweets are private between the sender and recipient. Tweets sent over SMS become DMs when they begin with "d username" to specify who the message is for. Learn more about direct messages."

#GFF - This is one that you should avoid at all costs, according to Twitter's official glossary, which has this to say about it: "Sites that promise to get you more followers if you provide your username and password. After signing up, these sites send spam from your account. Don't use them."

RT - Another one best left to the official Twitter glossary, which defines it as: "Abbreviated version of "retweet." Placed before the retweeted text when users manually retweet a message. See also Retweet. Find out more about retweets."

MT - One more that Twitter's official glossary define better than we can: "Similar to RT, an abbreviation for "Modified Tweet." Placed before the retweeted text when users manually retweet a message with modifications, for example shortening a Tweet."

We hope this glossary has been helpful, and once again invite you to add any hashtags, abbreviations or slang terms we may have forgotten (or that come out after this article is published), or to point out any possible corrections to the definitions we have offered.