ichidan verb, transitive verb
lean something against; prop something against
Transitive verb: you place an object so that it rests against another surface for support. Often used with 壁 (wall) or 椅子 (chair).
彼は壁にもたせ掛けて自転車を置いた。
He left his bicycle leaning against the wall.
I was tired, so I leaned my body against the sofa.