Shoes worn outdoors; the opposite of indoor shoes (上履き), often contrasted in school contexts.
学校では下履きを玄関で脱いで、上履きに履き替える。
At school you take off your outdoor shoes at the entrance and change into indoor shoes.
雨の日は下履きが濡れるから、替えの靴を持っていったほうがいい。
On rainy days your outdoor shoes get wet, so it's better to bring a spare pair.
運動用の下履きをしっかり履いて準備運動をする。
Put on your athletic outdoor shoes properly and warm up.