great mountain; large mountain
A learned or elevated noun for a very large, imposing mountain. In everyday speech, 大きな山 is usually more natural; 大山 often appears in literary phrasing, set expressions, or figurative comparisons.
A great mountain towered before us.
The saying “a great mountain rumbles and only one mouse appears” means that a huge fuss produces only a tiny result.
Several great mountains loom along the border.
From the summit, we could gaze upon a great mountain in the distance.
小山 is a small hill or hillock, the direct opposite in scale to the grand, towering 大山.
much ado about nothing; big fuss over nothing