It's likely you're thinking of a specific context where "vigruthi" is used to refer to a year. Could you provide more context? For example:
* Is it a year in a calendar system? If so, what calendar system?
* Is it a year within a specific historical period?
* Is it a year related to a specific event or era?
With more information, I can help you understand the meaning of "vigruthi" as it relates to a specific year.