So, it seems HIDDEN YEARS might have cracked this code.
During Starfall, Starrise:
Near the beginning of the story it says, "...Wolfriders stir from their peaceful daysleep."
SHREEAH OLIN TYL.
We all know this is some form of expression for a good sleep, perhaps specifically for Wolfriders.
SHREEAH containes the word "AH" which we have determined to mean "LIGHT"
So, SHREE become "DAY"
SHREEAH = DAYLIGHT
TYL = GIFT
Which left me wondering as to what OLIN means. Something like sleep. But also peaceful. Then I got to thinking, as some other fans have mentioned, I'm thinking perhaps A BIT TOO HUMAN!
OLIN means sleep but much more than that. It's almost HIBERNATION. A deep, long, peaceful sleep full of dreams.
DAYLIGHT PEACEFUL/HIBERNATION/SLEEP GIFT!
This is what it means. Perhaps it's a short, more colloquial form of the full expression, but it works. Just like we say " G'night" or "nighty-night" instead of the formal "I wish you a good night."
This also works for OROLIN. (EVERY WORD HAS TO WORK IN EVERY PLACE)
OR = LONG
OLIN = PEACEFUL, DREAM SLEEP
This is a perfect name for the High One tasked with turning the scroll of colors while dreaming for centuries upon centuries.
This does leave me to wonder as to whether or not "O" is a prefix, much in the way of a superlative or meaning "ful" as "O" does at the end of the word. If we were focused on word gender this might be easier. Some words are clearly gender specific (CHEI = Masculine BELOVED, CHAI = Feminine BELOVED) so it will take some more time to figure all of this out.