Any person of humble social origins who aspires to be a member of a higher and / or more affluent social circle. In order to qualify as a 'social climber' this person must first and foremost be an utter liar and one who will stop at nothing to shamelessly promote themselves above their social standing and ABILITY. For example, they went to a Polytechnic which suddenly translates into Eton followed by Durham University. They bullshit to the Boss about how hard working they are at the expense of their truly industrious, focused subordinates. In other words they are capricious and will stop at nothing to fuck you over and get promoted. They think they've 'made it' to the higher echelons when they've acquired a low spec BMW or Audi Q5 (insert name and model of other expensive motor vehicle) even though they had to take out a high interest dodgy loan to 'buy' this 'bauble'. They gossip and slag everyone off; they call people 'tramps' and such like when they look like shit themselves. The social climber will typically try to associate with completely higher ranking people, thus living beyond their means and totally ignore those of a lesser rank than themselves (particularly at social functions). It's all smoke and mirrors, networking and consolidation loans. They are so self indulgent that they fail to realise that their act is paper thin and their betters laugh at how ridiculous they are.
Person A: I've secured myself an invite to the Colonel's Dining Out.
Person B: Really, I didn't know about that.
Person A: (Smug) Of course you didn't, you're on duty call out anyway and your wife has to baby sit for us.
Person B: What, again? Fuck off you social climbing fakers.
Man: But I can't even play golf, what the deuce? I don't even own golf clubs!!!
Ambitious Wife: Buy some on the credit card. The big boss plays golf and you need to network!!!
Man: Yes your Highness.