Looking up...
A large natural elevation of the earth's surface rising abruptly from the surrounding level; a large steep hill.
泰山是中国五岳之首。
Mount Tai is the foremost of China's Five Great Mountains.
In Chinese, 山 can also metaphorically refer to a large number of similar things (e.g., 一山的书 'a mountain of books').
The character 山 resembles three mountain peaks. Imagine climbing up and down the three peaks to visualize the character.
When 山 appears in a place name (e.g., 泰山), it is typically pronounced 'shān' and means 'mountain'. However, in some contexts like 山东 (Shāndōng), it refers to a province named after Mount Tai.
The character 山 (shān) depicts three mountain peaks in oracle bone script (甲骨文), representing the concept of a mountain. It has been consistently used to mean 'mountain' since ancient times.
山 is a common noun in Chinese and is often used in place names (e.g., 富士山 'Mount Fuji'). It can also appear in compound words like 山水 'landscape painting' or 山水画 'scenery'.