a hiker who wears a backpack
"After weeks of hiking through the Swiss Alps, she finally removed her worn-out backpacker gear to celebrate reaching the summit."
A traveler whose luggage consists of a backpack; especially, such a traveler who uses hostels, public transport, and other inexpensive services.
"After years of staying in luxury hotels, she finally decided to become a true backpacker by sleeping in hostel dorms and navigating the city on a budget bus pass."