1. at the side of or in a parallel position to sth, as well as
alongside the river/wall
'Alongside' can be used to describe a continuous movement: "When I run, my dog runs alongside me." It can also be used when the movement is happening in relation to something that is also continuous, like a wall, a street or a body of water: "I walked alongside the road toward the school." It is also used to describe events that happen parallel to each other or at the same time: "We can have the blood drive take place alongside the other events."