Find out what Instagram, Twitter and Reddit terms like WCM, MCM, TBT, LB, WTF and HMU mean. Instagram

Sometimes, going on the Internet is like entering a foreign land where you don't understand the language. While most teenagers and seasoned netizens might know what most hashtags, terms and abbreviations on sites like Instagram, Twitter and Reddit mean, not everyone is familiar with them. This article is for those who raise an eyebrow when they see hashtags like WCW and TBT or think LOL means “lots of love.” There are dozens of shortcuts used on the Web and social media -- the following glossary explains some of the more frequently used ones.

LOL, LMAO, ROFLMAO, ROLF: These are all ways to laugh online. Instead of saying “haha” or “hehe” people will typically write LOL, for “laughing out loud.” If it’s even funnier, then people will use “Laughing my a-- off.” Those who have a penchant for cursing might add an F in there. ROFL stands for “rolling on the floor laughing,” and so on.

MCM, WCW: These terms are how people give a shout-out to their crush, whether it be their boyfriend or girlfriend IRL -- we’ll get to that abbreviation in a moment -- or celebrity crush like UFC fighter Ronda Rousey. MCM is used on Mondays for men and means “man crush Mondays”; WCW is used on Wednesday for women and means “women crush Wednesdays.”

TBT, TT, FBF: These terms are for types of flashbacks, to show friends and family a glimpse of the past. TBT stands for “throwback Thursday” and is one of the most popular hashtags. TT stands for “transformation Tuesday” and is usually used to show a change in appearance (weight loss, haircut, etc.). FBF stands for “flashback Friday” and is pretty much the same as TBT, except it’s used on Fridays.

LB: This is a newer term. It can be seen on the pages of celebrities and means “like back.” Kylie Jenner yelled at her Instagram followers for writing LB on her pictures. “STOP WRITING LB ON ALL MY INSTAGRAM PHOTOS AND USING ME AS A WAY TO ADVERTISE YOURSELF,” she wrote in 2012.

WTF: This is shorthand for “what the f---.”

HMU: “Hit me up,” which is another way to say “call/text me.”

DM: “Direct message.” On social media sites like Twitter and Instagram, every follower can see comments. To keep a social media conversation more intimate, direct messages can be sent.

TIL, IRL: Popular on Twitter and Reddit, TIL stands for “today I learned” and IRL is “in real life.”

Stay tuned for updates and tweaks ...

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