A quick online search for the definition of "Adventure" produces this:
ad·ven·ture (

d-v

n

ch

r)
n.
1. a. An undertaking or enterprise of a hazardous nature.
1. b. An undertaking of a questionable nature
2. An unusual or exciting experience
3. Participation in hazardous or exciting experiences
4. A financial speculation or business venture.
v. ad·ven·tured,
ad·ven·tur·ing,
ad·ven·tures
v.tr.
1. To venture upon; undertake or try.
2. To expose to danger or risk; hazard.
v.intr.
1. To take a risk; dare.
2. To proceed despite risks.
So if what you are doing is hazardous, questionable, exciting and risky then it is an adventure!
For me riding to Taoz in Southern Morocco was an adventure, yet I had a book of routes to follow, GPS, a credit card and a mobile phone.
Perhaps if I'd done it without any of the modern gadgets it'd have been more adventurous, but then, I enjoy those things so would it have been as much fun for me?
Dunno. Each to their own. Personally, anything outside Europe or the States would count as an adventure to me.