Adulting ( verb ): To do grown-up things and hold responsibilities such as having a job, paying rent or doing laundry. A verb used exclusively by those who adult less than 50 per cent of the time. If you've forgotten to pay your council tax, you're hungover at work (again) and you've been living off pesto pasta for the past seventeen days, it's time to adult. Authentic grown-up Stephen Wildish has produced a book for everyone who feels they need assistance getting through the confusing landscape of the real world.