It is used to refer to:
* An explanation or clarification of something.
* A detailed account or description.
* An interpretation or analysis of something.
For example, you could say:
* "Please give me a vilakkayatam of this situation." (Please explain this situation to me.)
* "The book provides a clear vilakkayatam of the historical events." (The book gives a clear explanation of the historical events.)
Let me know if you have any other Malayalam words you'd like to know the meaning of!