Is there a word to describe an appearance between pretty and ugly?

Solution 1:

https://forum.wordreference.com/threads/plain-person.2722815/

"If you call a woman "plain", you're saying that she's not pretty - though you're not saying that she's ugly."

That being said, I could imagine a context in which "plainness" would be seen as a positive quality - it could be seen as positive through comparison with people who care too much about their appearance. I could also see something like "She was a plain farmer's wife, with the same blank beauty as the prairies that surrounded her."

The term, "blank beauty" is an interesting turn of phrase, to me.

https://www.lexico.com/definition/plain_looking

plain-looking:

ADJECTIVE Not beautiful, distinctive, or remarkable in appearance.

unadorned

lacks distinctive beauty

modest looks

of ordinary attractiveness