“Gloat” does not mean anything like what I thought it meant.  “Gloat” is to gaze – askance, furtively, amourously, admiringly, in its obscure meanings, which predate the current one.  Here we are now:

To gaze with intense or passionate satisfaction (usually implying a lustful, avaricious or malignant pleasure). Now almost exclusively to gloat on, upon, or over : to feast one’s eyes upon, to contemplate, think of, or dwell upon with fierce or unholy joy.

The first use of it is given from Clarissa, which perfectly illustrates the creepiness factor.  This third sense has something to do in its origins with “glut”.  It comes from German, Swedish, and Old Norse words for “glare”, “peep”, and – get this – “grin”.

Now, I have always thought that “gloat” is like “boast” – something one does with words, not eyes, but definitely related to avariciousness and thus to pride.  Tolkien used it in this way in the quotation under consideration:

Now I am old and strong, strong, strong, Thief in the Shadows!’ he gloated. ‘My armour is like tenfold shields, my teeth are swords, my claws spears, the shock of my tail a thunderbolt, my wings a hurricane, and my breath death!’

The Merriam-Webster dictionary gives us something to hold on to:

• 12.072 he gloated.

Great elephants, but I love this project!

“gloat.” Merriam-Webster. Merriam-Webster, n.d. Web. 26 July 2015.

“gloat, v.” OED Online. Oxford University Press, June 2015. Web. 26 July 2015.

This word for twilight, or less commonly dawnlight, is related to “glow” and to the second word “gloom” – “heat of the sun”, from which we get “gloom-stove”, a drying oven for gunpowder.  This “gloom” is completely separate from the “gloom” which has to do with staring and the origins of “glum“.  Possibly from Old English “glóm”, but not for sure.

• 08.131 to the gloaming
• 19.003 On hearth in the gloaming

“gloaming, n.” OED Online. Oxford University Press, June 2015. Web. 26 July 2015.

“gloom, n.2.” OED Online. Oxford University Press, June 2015. Web. 26 July 2015.

Roots of this word have to do straightforwardly with shining and may derive from a pre-Germanic root ghlid- which relates to the Greek word for luxury!  The OED entry for this word – to shine brightly but flickeringly – includes this example from Samuel Johnson.

1784   Johnson Let. 2 Oct. (1994) IV. 413   All is not gold that glitters, as we have been often told.

Ahem.  Yes, we have often been told, Mr. Johnson.  And that wise saying may have morphed over time.  But that’s a different story.

• 08.059 in rockets of glittering sparks
• 13.042 Their glittering mail they had covered again
• 14.023 his belly glittered white with sparkling fires of gems

“glitter, v.” OED Online. Oxford University Press, June 2015. Web. 26 July 2015.

This noun for gleam or shine has a Scottish meaning of glance.  Here’s that crossover again between the light and the view of the light – Aha!  the verb “glint” – to shine with a flashing light – has a Scottish meaning of quick movement, specifically including a quick movement of the eyes, therefore to peep.

The word comes from “glent”, a lovely obscure word for quick motion, related to glide, slide and here’s a clue!

The original sense is probably that of quick motion, the application to light being secondary;

Quick motion of light.  There we go.

• 06.067 Also he could see the glint of the moon
• 08.071 and white gems glinted on their collars
• 13.009 there was a pale white glint,
• 13.018 they caught a glint
• 13.019 shot with glints of the rainbow.
• 16.036 in a net woven of the glint of frosty stars.

“glint, n.1.” OED Online. Oxford University Press, June 2015. Web. 26 July 2015.

“glint, v.” OED Online. Oxford University Press, June 2015. Web. 26 July 2015.

This word has rather obscure etymology, but may, through its meaning of a sunny place in the woods, be related to “gleam”!

• 03.012 when they came at length to an open glade
• 06.052 and they ran to the trees at the edge of the glade,
• 06.052 a large pine standing at the very edge of the glade.
• 06.060 This glade in the ring of trees
• 06.060 in the glade;
• 06.065 Very soon all about the glade wolves were rolling over
• 08.099 in the glade where they lived,
• 19.001 into the lower glades of the wood

“glade, n.2.” OED Online. Oxford University Press, June 2015. Web. 26 July 2015.