it's the term that popularized it and gave it the 'chic' status.
It's basically a perpetual desire to travel and explore the world. 

People travel for all kinds of reasons-
for work, for family, for friends, for leisure.
'My boss said I have to go to Guangzhou to settle...'
"there's an incredible shopping mall 10 times bigger in Bangkok...'
'I'm going back to Penang for the weekend cause my mom told me..'

But these are all the superficial kind of reasons you/i/we/they travel.

What's your true reason for travelling?

For me, first and foremost, it's because of the wonder; because of this connection.
Every time I travel, I experience this quite spectacular feeling of being something really small, yet significant.
 Something small, such as a petal, or a feather, but part of something much huger, much more wholesome, much more incredible.
It's the feeling of being completely at ease with yourself, and perfectly adequate.

It's also because, though I was born in and have grown up in Singapore, 
some part of me believes that, somewhere else on this planet,
There exists a place where I would experience a sense of comfort and peace that I can find no where else.
(And) perhaps I would make that place my eventual home. 

I haven't found that place yet, 
but I still keep looking.

What about you? Why do you travel?