As one of my readers, Suzanne, wrote: "I think it must have something to do with 'light', if, that is, the word is of Latin origin... Lucia, Luz and all that! Otherwise, it's my cousin Lucy's nickname!"
Interestingly, two of those offering submissions made the same assumption, David Weeks suggested:
Luce is the light that is seen when awaking after having over-imbibed the night before.
While Gill proposed:
Luce [pronounced "loochay"]. Light, specifically light at the end of a tunnel used literally by the miners of the Roman Empire and figuratively by their patrician counterparts when plotting the murder of Emperors [as in "Today Cassius there will be luce!"].
I am sad to report that non-mining plebeians used it to describe relief from constipation.
Another entrant, who was captivated by the word's potential Latin origin (and who, at least, agreed with the pronunciation above), was Boll Weavil:
Luce [pronounced "Loo-ch-ay"]. A man or woman who becomes obsessed with something that is known to be fictitious to the extent that it takes over their life and becomes real. The word comes to us as a result of the Emperor Luce who, allegedly, was so interested in a dramatic text set around the feast of Saturnalia, that he surrounded himself with reminders of that festival every day of the year and frequently commanded performances of the text for his personal viewing.
Historians of the time recorded that although he frequently took on the persona of the characters involved, he was, in all other respects, able to rule and live out a normal life. The reason the word has fallen into disuse nowadays is that there is simply no modern-day equivalent character. If there were, we would deem them eccentric at the very least!
From Ryan Rasmussen came the erudite suggestion:
A graduate student who attempts to speak like Foucault writes . . . and ought to know better.
Good Dog came up with the implausible (but certainly amusing) suggestion:
Luce - a range of IKEA stools that never quite took off in the public's imagination.
And there were also two more variations - each with variant pronunciations - from Gill:
Luce [pronounced "loose"]. Regency word for a lady of the night. Gentlemen believed that, if Latinised, the women and servants would not understand the word if they saw it written.
Luce [pronounced "lussy"]. Victorian term for a young girl on the edge of sexual exploration, the step before "hussy".
Many thanks for all the laughs, Wordsmiths!
So, what about the real meaning of the word...?
Well, Gill ended her submission by saying, "Or it could be something really boring --- like a fish..." which is curiously close to the truth, since ONE definition of LUCE is:
"The heraldic representation of a pike..."
It is interesting to note that, "The pike is a symbol for a military family and indicates prowess and fortitude in bearers of this charge. This fish is also a symbol of the forces of industry and science and early Christians frequently used the pike as an emblem of their faith."
However, it is clearly a word which (with all due respect to fish and heralds) is of little use in daily life - unless you just happen to be Garter Principal King of Arms!
But LUCE has yet another definition...
It is, in fact, a Scottish word defined in John Mactaggart's Scottish Gallovidian Encylopedia of 1824 as:
"A blue matter which is scraped off the face
Useful! Needless to say, the word for any red stuff mixed in with the blue is BLOOD!