MENTAL

Memorándum. n.s. [Latin.] A note to help the memory.

I resolved to new pave every street within the liberties, and entered a memorandum in my pocket-book accordingly. Guardian, № 166.

Nature's fair table-book, our tender souls,
We scrawl all o'er with old and empty rules,
Stale memorandums of the schools. Swift's Miscel

Mércurial. adj. [mercurialis, Lat.]

1.   1. Formed under the influence of mercury; active; sprightly.

I know the shape of 's leg: This is his hand,
His foot mercurial, his martial thigh,
The brawns of Hercules. Shakesp. Cymbeline.

This youth was such a mercurial, as could make his own part, if at any time he chanced to be out. Bacon's Hen. VII.

Tully considered the dispositions of a sincere, more ignorant, and less mercurial nation, by dwelling on the pathetick part. Swift's Miscel.

  2.  Consisting of quicksilver.

  

I was looking for a definition of "Mental" in Dr. Johnson's 1755 Dictionary, but he didn't include the word.  Bracketing what would have been its space on the page were "Memorandum" and "Mercurial," both worth sharing at the end of a "mental" week.  ("Old and empty rules, Stale memorandums of the schools" -- that's great senior year back-to-school material.)  

I was surprised to find "skellum," a commonly used term from my Brooklyn DA's Office days (usually abbreviated to "skel" or "skels" ), but used nowhere else, defined.  I was always told that the word derived from old Netherlandish, but I suppose I'll need to dig deeper later.



James Taylor: Knockin' Round The Zoo (Link) 

Definitions:  Samuel Johnson, The Dictionary of the English Language (1755)