Mastigophorous

Meaning: whip-bearing; used humorously* of British schoolmasters.

Usefulness: 1 ("Morning boss; looking particularly mastigophorous today." "You should all know that my approach to this year's budget will be mastigophorous."  Can obviously also be applied to jockeys, rodeo riders and other less savoury occupations.)

Logofascination: 1 (From the Greek for 'whip' and 'carrying', it's the sort of word Sir Thomas would have invented.)

Maranisados

Meaning: a racist epithet, this one word simultaneously insults Jews, Muslims and anyone who changed their faith - Cotgrave tells us that marrane (the French word Sir Thomas is translating) means:

A Renegado, or Apostata; a peruerted, or circumcised Christian; a Christian turned Turke, or Jew; also, a conuerted, or baptized Moore, Turke, or Iew; one that turnes Christian for feare rather then of deuotion; also, a Iewish, cruell, hard-hearted, or hollow-hearted fellow.

It's interesting that Cotgrave uses it of converts either way (to or from Christianity) as the OED and other sources only seem to have the sense of a convert to Christianity for reasons of fear or practicality. Cotgrave notes the element of fear in the conversion, but does not seem to see the contradiction inherent in the end of his definition.

Usefulness: 5 (Can't say I thought I'd ever feature a word this useless, but I don't think hiding from what makes us uncomfortable in a text is helpful.)

Logofascination: 2 (Sir Thomas has taken the French version, marrane, of what was originally a Spanish word, marrano, and re-Spanished it as maranisado; in fact he takes an entire phrase of which only one word is in Spanish in Rabelais and replaces it with Spanish.)

Seif

Meaning: a dune which elongates parallel to the prevailing wind; from the Arabic sayf, meaning sword.

Usefulness: 2 (depending on geography, although I suppose it could be re-adopted as a simile: "Like the seif, her tendencies follow the strongest influence.")

Logofascination: 2 (It's a beautiful word, possibly due to some mysterious Arabian-nights style glamour; a simple entry to ease back into it after all that nebrundiation.)