Mad, insane, bizarre. Can be used in reference to a person or a concept.
'Wow, she was a bit... different.'
'Different? She was right up the kitchen end!
She let her pet crocodile lay eggs in my abdomen.'
The general propensity for people to deceive. The 'real world' of conspiracy and exploitation.
'Are you sure about trusting a mysterious company with all of your belongings?'
'Surely no-one would set up a fake courier company on the off chance that they would be asked to transport something worth more than the cost of setting up the scam in the first place!'
'Never underestimate The Craft Market.'