word: megrims

I happened across this interesting word/phrase while reading Fundraising the Dead by Sheila Connolly -

"And, Nell? I'm sorry that you had to be the one to stumble into this. I hope you aren't too upset, because I need you to help me--help the Society--through this difficult time."
Well, it was nice that he had thought about it. But I had no intention of lapsing into a fit of the megrims, whatever they were. I would soldier on, and I would save any mourning for poor [so-and-so] until later, when I got home. (68, emphasis mine)

Now out of common usage, megrim means depression or dejection, low spirits.  The megrims are comparable to the blues.  It can also mean a whim / fancy / caprice, though I think that usage was less common.

Apparently this is where we get the word migraine.

There is also a type of fish called the megrim.  As I am not a fan of this class, I refrained from doing too much research into this particular usage of the word.  The megrim (according to the one image I saw) is pale (perhaps translucent) and has a strange, squashed-looking face.