Noun:
* It refers to a strong vertical support, often made of stone or concrete, used in buildings or structures.
* Example: "The ancient temple was supported by massive stone pillars."
Adjective:
* It describes something that is very important or essential, like a pillar of support.
* Example: "She is a pillar of the community, always willing to help others."
The part of speech depends on how it's used in a sentence.