A long and arduous journey, especially one made on foot. The explorers embarked on a trek through the dense jungle to reach the ancient ruins.
A migration or journey, often involving a group of people, typically over a long distance. The annual trek of the nomadic tribe across the desert is a well-coordinated event.
In South African historical usage, a journey or migration by ox-wagon, especially one undertaken by Boer settlers. The Great Trek of the 1830s saw thousands of Boers leave the Cape Colony.