1. (通常指徒步)艰难旅行，跋涉，远足
If you trek somewhere, you go on a journey across difficult country, usually on foot.

2. (通常因疲惫而缓慢勉强地)行进，拖着腿走
If you trek somewhere, you go there rather slowly and unwillingly, usually because you are tired.

1. any long and difficult trip

2. a journey by ox wagon (especially an organized migration by a group of settlers)