"trekking" in the verb sense
1. trek
journey on foot, especially in the mountains
"We spent the summer trekking in the foothills of the Himalayas"
2. trek
make a long and difficult journey
"They trekked towards the North Pole with sleds and skis"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License