This is the BBC . This podcast is supported by advertising outside the . This is a download from BBC Learning English to find out more . Visit our website . Six minutes from BBC Learning English dot com Hello , welcome to Six Minute Vocabulary . I'm Rob . And I'm Catherine . And today we're talking about new words . Yes , new words in English . We'll look at where they come from , why we need them and who uses them . We'll have a quiz and we'll also bring you a top tip for learning vocabulary . But first , here's Eiris talking about a photograph she took . And here's a question . Is Iris happy with her photo ? OK . So here's a selfie from a flash mob , I went to everyone dancing and stuff , and that's my idiot boyfriend at the back , he decided to photobomb me . It's quite funny , though . I put it on my social networks , but the trolls said , we look stupid . I don't care , though . I like it . So that's Iris , and she said she liked the photo good . Now , there were a few words there that are quite new in English . Let's have a look at some of them . Listen again to Iris to questions this time . One , what type of photo did she take and to where was she ? So he's a selfie from a flash mob . I went to . So I just took a selfie and she was at a flashmob , let's take those words one at a time . Yes , first of all , a very popular word . Now , selfie , that's a photograph you take of yourself by holding your camera or phone out in front of you at arm's length . Selfie . Take many selfies , Rob . Absolutely not . No , not at all . Don't look at myself . Thank you . But where does the word selfie come from ? Well , the word self-portrait has been around for a long time . It means a picture you draw or paint of yourself . So selfie probably comes from that . Yes . And that's one way words come into English , get an old word , change it to fit a new situation . And you've got a new word like selfie . And that's one reason why we need new words to talk about new situations like all these self portraits that everyone's taking . Yeah , good . Now , another way to make a new word for a new situation is to get to old words and put them together . Iris , was that a flash mob ? Now a flash mob is a crowd of people who gather together quickly and suddenly . It's often organized through social media . Now the word flash can mean something that happens very quickly . And a mob is a crowd of people . So when you put them together , you've got the perfect new word for the situation . Ever been on a flash mob , Rob ? I'm afraid not . Nobody's invited me and really to the next one . I go on . Thank you . Anyway , you've probably noticed that these words are mostly made by people on social media . It's not the only place that new words come from , but a lot of new words are coming from social media at the moment . Next example , Iris's boyfriend jumped into her selfie at the last minute is actually in the photo , even though she wasn't expecting him to be . And here's a word for it . And that's my idiot boyfriend at the back , he decided to photobomb me . So photobomb , that's a new word made from two old words , photo , obviously , and bomb , the thing that suddenly explodes and we've got similar new words like weather bomb . That's a sudden period of extreme weather . And then the thought bomb where people get together and basically think , yes , that's a new word for what we used to call brainstorm . It is . Yeah , very similar . Right . OK , well , now , Eiris used another new word to describe people who post horrible comments on social media . Listen carefully to this . I put it on my social networks , but the trolls said , we look stupid . A person who posts negative comments on social media is called a troll and troll is actually an old words for an imaginary creature , a kind of monster . You find lots of trolls in old Scandinavian stories and the word's been around in English for a long time . So an old word with a new meaning . But there's a link there to the original meaning , isn't there ? Yes , that's right . Because both kinds of troll are quite ugly in their own way , either in their looks or behavior . Six minutes from BBC Learning English . And we're talking about new words , so , Catherine , have you ever been trolled and thankfully I haven't , Rob , I choose my friends very carefully on social media . Right . It's quiz time . Question one , what's the word for a group of people who gather together suddenly and it's normally organized on social media ? And the idea is the word is flashmob question to what word means jump into someone else's photograph . That photobomb . Finally , what's the word for people who write nasty negative comments online ? They are trolls . OK , well done . If you got those right at home . Well done indeed . And now here's a vocabulary tip to keep your English right up to date . Join some social media groups where people use English . Social media is a great place to pick up words and expressions of , even though they're not in the dictionary . Yes , a new words are being invented all the time . And they they are . Yes . OK , well , there's more about this at BBC Learning English dot com . You can also find us on Twitter , Facebook and many other social networks , but don't . Yes , OK . Join us again soon for more six minute vocabulary . .