Meaning of Meaning

How does one arrive at what something means? Is it

• the end of a causal chain
• is it a sensation, a sense of understanding, a neurochemistry
• an assignment of value / importance / cause to a phenomenon
• a gestalt that is a combination of the above items

There are reports that moments of great insight, mushroom experiences generate this great sense of meaningfulness to existence. That meaningfulness seems to be an upper left quadrant experience. And does that imply that even though we cognitively tend to think of meaning as being absolute, it is almost always relative - to us, our neurochemistry, our ontologies, .... ??