somehow made the word make sense, even before reading the defs you provided.

Seeing "To enter their courts is simply to be mulcted of our meager means . . ' gave me the meaning, in modern jargon of 'to have our shallow pockets sucked dry by court costs' which might be a near-enough translation.

And like you, I love writing that makes me learn new (to me) words. If I had the kind of dictionary that gives the derivations of words as far back as our knowledge goes, I'd look it up. Without such a resource, I'd guess that (after the deep history) it comes from some stage of early English, and I'd guess that it might be a form of 'milked'. As a writer's word choice for that sentence, its a great one for both rhythm and alliteration. Imagine this line in a Shakespeare play --

'To enter their courts is simply to be
mulcted of our meager means;' --

Perfectly Shakespearian rhythm; and if 'mulcted' was understood as 'milking us dry' its emphasized placement carries a lot of emotion.

Earlier generations of writers were taught to consider elements, like rhythm, in ways that have fallen out of use, which I regret. The last writers (in politics) that I know of who wrote with those older considerations were JFK and RFK, whose Catholic-school near-classical educations trained their writing-minds in those old practices. Churchill was a master of them. I don't think anybody schooled after the 60s even came into contact with them -- a real loss to the culture, I think.