Easter rare in yesterday's 10 letter puzzle

[yelnats]

I was very surprised that "easter" was classified as a rare word in yesterday's 10 letter SEAMSTRESS puzzle, while ester was common.

[Morbius]

I don't think it refers to Easter, the Christian festival, which is spelt with a capital 'E' and is therefore not a valid word in Chi.  I think it's an archaic term meaning 'more east'.  Wester is also playable in Chi, and I'm pretty sure norther and souther have come up too, all as rare words.

[yelnats]

Thank you. I stand corrected...

[ensiform]

It is typically a word for an eastern wind.  Still used today in seafaring.