The term high can have various meanings depending on the context in which it is used. Generally, when referring to a state of mind or physical sensation, high means elevated or exaggerated. For example, someone might say they feel “high” if they are feeling very happy, excited, or elated.
In terms of drugs and substances, the word "high" typically refers to being under the influence of a drug that causes an altered state of consciousness or heightened sensory perceptions. For example, someone who takes marijuana might experience a “high” feeling due to the effects of THC on their brain.
In other contexts, high can refer to something or someone that is elevated physically or metaphorically. For instance, a mountain range could be described as being "high" because it rises above its surroundings. Similarly, someone who achieves great success in life might be referred to as “high” on their accomplishments.