The only place I have ever seen this word is in anatomy. The Fallopian tubes of the uterus have
funnel shaped ends that partially enclose the ovaries, and has fimbriated (finger-like) projections.
Considering the accursed abundance of pornography on the Internet, it is pathetic that i was
unable to find URL to show a picture of this.

firth
n.
5ME < ON fj;rthr, akin to OE ford, FORD6 a narrow inlet or arm of the sea; estuary

As in the Firth of forth. But there is no Firth of Fifth.

From Macbeth:..... Duncan is in his grave; after life's fitful fever he sleeps ...

fitful
adj.
5FIT2 + 3FUL6 characterized by irregular or intermittent activity, impulses, etc.; spasmodic; restless
fit4ful[ly
adv.

flacon
n.
5Fr: see FLAGON6 a small flask with a stopper, as for holding perfume

Apparently Gaelic.flaith' is a(n) Noun, with simple translation 'prince'.

In early days of jet fighters, "flameout" sometimes compelled pilot to eject.

flange
n.
5< ? ME flaunch, a lenticular space on a coat of arms < OFr flanche, side, var. of flanc: see fol.6 a projecting rim or collar on a wheel, pipe, rail, etc., to hold it in place, give it strength, guide it, or attach it to something else
vt.
flanged, flang4ing to put a flange on

Confusion of these two used to be common. "flair" is from a French word, referring to a hunting
dog's ability to discover game ;(or even truffles) and was used as a metaphor meaning a talent
for discovering tasteful new styles, etc.

flare
vi.
flared, flar4ing 5ME fleare < ?6
1 a) to blaze up with a sudden, bright light b) to burn unsteadily, as a flame whipped about by the wind
2 to burst out suddenly in anger, violence, etc.: often with up or out
3 to curve or spread outward, as the bell of a trumpet
vt.
1 to make flare
2 to signal with a flare


flair
n.
5ME, odor, fragrance < OFr < flairer, to emit an odor < LL flagrare, for L fragrare, to smell, reek < IE *bhrag3, prob. < base *bher3, to boil up > BARM, BREATH6
1 orig., sense of smell; hence, keen, natural discernment
2 a natural talent or ability; aptitude; knack
3 [Colloq.] a sense of what is stylish and striking; dash

Fimbriation is also an armorial term. In describing a "coat of arms" there are several colors (technically "tinctures") referred to, two of which are referred to as metals (silver and gold, i.e., argent and or) and five colors (red, blue, green, purple and black, i.e., gules, azure, vert, purpure and sable). It is not permited to have a metal on a metal or a color on a color, so, if fate decrees that this happen, a thin border of the other (i.e., metal separating colors or color separating metals) is added to the design. This thin border is called fimbriation. The Cubs' baseball cap could be described as azure a block letter C gules, fimbriated argent.

A French word for a disease of wine grapes. A golden yellow color.
"Les jaunisses de la vigne causées par des phytoplasmes sont en extension dans la plupart
des pays viticoles. La France et l'Italie connaissent la flavescence dorée, maladie très épidémique
transmise par une cicadelle vectrice ampélophage. Le bois noir a été identifié et est très répandu
dans tous les pays viticoles de l'Europe de l'Ouest et en Israël. D'autres jaunisses sont jugées
préoccupantes aux États-Unis et en Australie. Les phytoplasmes sont des parasites stricts encore
mal connus. Les méthodes de diagnostic des jaunisses de la vigne ont cependant fait des progrès considérables, qui permettent maintenant des études épidémiologiques et la recherche de méthodes
de lutte, préventives et prophylactiques. Les phytoplasmes sont transportés par les
bois de multiplication de la vigne.

Some of these spellingbee words are for the birds. I could find no definition for this word,
though it was in several Scrabble word lists.
Maybe meaning somebody who processes flax?

Flixweed, a winter or early
spring annual sometimes called
tansy mustard, occurs in waste
areas, fields, roadsides, and
ditchbanks in central and
eastern California. Seedlings
have long and narrow leaves on
fine haired stalks. A stub
remains when cotyledons are
shed. The first pair of true
leaves appear to be opposite.
Somewhat thick, the leaves are
alternate and covered with
white downy, star-shaped hairs.
Mature plants, up to 2 feet (60
cm) tall, have yellow flowers
and finely dissected leaves.
Erect branches have long,
flowering stems with seed pods
about one inch (25 mm) long.

From MW:

Main Entry: flaxy
Pronunciation: 'flak-sE
Function: adjective
Inflected Form(s): flax·i·er; -est
Date: 1634
: resembling flax especially in texture

her hair is flaxier than hers...…

Yes, but hers is flaxiest!

And some flacks are flaxier than others.

some flacks are flaxier

Careful, Dr Bill. You might end up taking some flak for that one.