[verb]If a slope steepens, it becomes a sharper angle.As we got nearer to the mountains, the road began to steepen. [I]If we steepened the steps (= made them have a sharper angle) down to the cellar, they'd take up less space. [T]If something such as a cost steepens, it increases.Our costs have steepened since we began this project.
STEEPEN
Meaning of STEEPEN in English
Cambridge English vocab. Кембриджский английский словарь. 2012