To me, adventure means stepping out of your comfort zone and breaking from the monotony of what is expected. It means taking a risk and challenging yourself. If the thought of what you're about to do doesn't leave you with butterflies in your stomach, whether that be due to excitement or fear, then you're not doing it right.
Travel provides so many opportunities for adventure, from the anticipation of boarding a plane bound for a new destination to mixing with strangers from other cultures and attempting to communicate in another language. It allows you to experience unusual practices, volunteer with disadvantaged communities and witness incredible spectacles.
Challenging yourself to try new things will give you an adrenaline buzz like no other. Throwing yourself from a plane, or indeed flying one upside down, should do it. As should leaping from a platform with a bungy cord tied around your ankles. But you don't have to terrify yourself to be adventurous.
Step outside your front door and head in the opposite direction to normal or try something regular in an unfamiliar environment. Eat lunch in the centre of a deserted salt plain, stay overnight with a Maasai tribe and teach their children Gangnam Style, camp out among the lions of the Serengeti, admire Rio Carnival from a concrete step for a full 10 hours, hike beautiful landscapes until your calves scream out in protest, or simply make a decision to try something new the moment you get out of bed.