Valedictorian used as a noun in 1832, adj in 1834. American English. From Valedictory adj. and -ian variant of -an, Middle English -ien from French loan words, -an "pertaining to" from Latin -anus.
Valedictory first used in the 1650s, from the Latin valedictum from valedicere and -ory from Latin -orius, -oria, -orium "to have a quality proper to the action accomplished by the agent".
valedicere from vale, imperative of valere "be well" and dicere "to say". See also "Valediction" from 1610s.
Validate v. from 1640s from Latin validatus, from validus, from valere "be well", "be strong" (connoted)
I stand corrected--I had understood the original comment as something that contradicted mneary's reply, and I knew the specific etymology of "to bid farewell" just didn't look at the full derivation.
No problem, I missed the edit window on my reply when I realized it might be a little bit terse sounding in tone. I meant it as being helpful.
I'll add that the Latin vale can be used to mean "farewell", which is usually how it's translated, but if you dig down the etymology rabbit hole, they come from two different language families and not surprisingly don't mean the same thing.
"farewell" is from somewhere between 1200 and the 14th century middle English, a composite of faren "fare" and wel "well". The phrase used to be "fare thee well" but was contracted later. All have Germanic roots.
"fare" is old-English fær means "to go forth on a journey" and still hangs around in some words like "sea-faring", "wayfarer" and "farewell" ("fare" eventually turned into the more modern meaning "payment for passage or conveyance", but that's a digression).
"well" in the sense of "farewell" these days connotes good health (as in "are you well?") but originates also in Germanic tongues to mean "satisfactory".
"thee" is also proto-Germanic in origin and I won't belabor it.
Swedish speakers may recognize this in the modern form as "farväl" and Dutch as "vaarwel"
A "valedictory" is usually translated as "a farewell address" and the act of the speech the valedictorian gives is called a "valediction" (a farewell). But this isn't strictly correct. "valedictory" means something more like "words for good health".
So it's more like we commonly translate "hope you feel well!" to "have a safe trip!" which isn't really quite right.
It's interesting then that:
a) "well" has come to adopt the Latin meaning "health" in the sense that "valere" means "well" i.e. "health" (similar to "valetudo" or "valetudinis"). "valere" more strictly translates to "health" (which all the other meanings connote e.g. "strength" "well" etc.). Also found in words like "convalescence" with the "strength" connotation ending up in words like "valiant" and "validity". When we "validate" something, we are proving it to be strong, which is a connotation of "healthy". So it really means "to prove to be healthy".
b) We define Latin words in terms of Germanic explanations, but not the other way around. e.g. if you look up "farewell" in the dictionary it's not defined as a "valediction". Which would come as no surprise to those that know that English is a Germanic language.
I'll walk you through it.
Valedictorian used as a noun in 1832, adj in 1834. American English. From Valedictory adj. and -ian variant of -an, Middle English -ien from French loan words, -an "pertaining to" from Latin -anus.
Valedictory first used in the 1650s, from the Latin valedictum from valedicere and -ory from Latin -orius, -oria, -orium "to have a quality proper to the action accomplished by the agent".
valedicere from vale, imperative of valere "be well" and dicere "to say". See also "Valediction" from 1610s.
Validate v. from 1640s from Latin validatus, from validus, from valere "be well", "be strong" (connoted)