I heard this last evening on The Bill O’Reilly Show on Fox News Channel.

Question:
What is the difference between “relevancy” and “relevance”?

Explanation:
The host of the show asked a guest, “Does that have any relevancy [to the topic being discussed]?”

The word “relevancy” struck me as odd, given that I grew up using the word “relevance”, so I researched these two words.

According to Merriam-Webster’s Online Dictionary:

• “relevancy” is a noun that dates back to 1561 and today primarily means relevance;
• “relevance” is a noun that dates back to 1733 and today primarily means relation to the matter at hand.

This gives us the answer to the question.

Answer:
There is no difference in primary meaning between between the older noun “relevancy” and the younger noun “relevance”.