What's going on with adjectives ending with や?


I was looking into a presumably older song, Gion Kouta, and I noticed that one
of the lyrics is 「恋しや」. I'm assuming this comes from the adjective 「恋しい」, but
I don't know why 「や」 is used instead of 「い」. Does 「や」 make 「い」 adjectives into
nouns? Is it an older adjective ending? I'm confused about this.




恋し is the classical Japanese form of 恋しい. It is already in its terminal form
(終止形) so や is just an exclamation word here.

You can check the conjugation table
[here](https://en.wiktionary.org/wiki/%E6%88%80%E3%81%97#Japanese).

