While searching for something else, I found this word:"alethia".
I'm surprised it hasn't been used as a girl's name. It reminds me
of Prince Valiant's wife, Aleta, (If I remember correctly.)

"
The Greek word that is translated truth in the New Testament is a very powerful and
meaningful word. It is alethia."

I found this word:"alethia". I'm surprised it hasn't been used as a girl's name.

Isn't that the first name of pianist Della Rocha? that's "Alicia," actually

It has: http://aupanthers.ocsn.com/sports/c-xc/mtt/ali_alethia00.html and http://www.bracepatt.com/professionals/detail.asp?ID=184to give just two.

Bingley

Although many name-meaning sites, among other sources, seem to translate it as truth this site:
http://www.messianic.com/yeshua/preface.htm
points out that, at root it means not to forget.

It's down in the penultimate paragraph.

Lethe (LEE-thee)


A river in Hades whose waters caused
forgetfulness. It was on the banks of another
Underworld river called the Styx that the
shades, or ghostly remains, of the dead
congregated to seek passage to the Afterlife.
Unless they bribed Charon to ferry them
across the stream, they wandered aimlessly on
the near bank forever. But those who made it
across the Styx did not have much more to
anticipate. Once they had drunk from the
waters of Lethe, they were left with nothing to
reminisce about for eternity.

But "lethal" meaning capapable of causing death is from Latin:
lethal


SYLLABICATION:
le·thal
PRONUNCIATION:
lthl
ADJECTIVE:
1. Capable of causing death. 2. Of, relating to, or causing death. See
synonyms at fatal. 3. Extremely harmful; devastating: accusations lethal to
the candidate's image.
ETYMOLOGY:
Late Latin lthlis, alteration (probably influenced by Lth, Lethe) of Latin
ltlis, from ltum, death.
OTHER FORMS:
le·thali·ty (l-thl-t) —NOUN
lethal·ly —ADVERB