Pretty self-explanatory - someone who thinks they're a hipster.
This type of person is in abundance on Twitter, usually with the screen name 'Sheldon Cooper'. They also have a habit of ending tweets with 'though', despite the actual tweet having no relation to anything. They also use other annoying buzzwords on Twitter. In addition to this, they think that liking The Big Bang Theory and bacon makes them look really edgy and random, and they all seem to think they're socially awkward despite tweeing their life stories to thousands of followers.
Commonly confused with real hipsters. However, whilst real hipsters stay true to the definition and listen to obscure, unheard of musical acts, Hipster Wannabes like currently popular acts despite them thinking that they're alternative for doing so, such as OFWGKTA, You Me At Six, Two Door Cinema Club, Arctic Monkeys and Foster The People.
They are an evolution of the Scene Kid from the mid-2000s, only more obnoxious and pretentious, and even less self-aware.
Real Hipster: "I think I'm gonna listen to some Ariel Pink's Haunted Graffiti and then head out to drink some Hungarian lager whilst discussing the latest Sufjan Stevens record"
Hipster Wannabe: "Socially awkward but happy because bacon, The Big Bang Theory and You Me At Six though ok"