I didn't expect that bringing up "peaked" as an adjective meaning "looking pale" would be all that controversial, at least not to AE speakers. I must have first heard the word as a child, probably 8 or 9 years old, from my mother. At that time, I'm sure I did not know the word "piqued" at all, so there couldn't have been any confusion. My mother was a high school English teacher with a master's degree in Library Science. The pronunciation with two syllables and long "e" is the only way I have ever heard it pronounced. The second pronunciation in the Webster entry with long "i" is new to me as well, but the fact that pronunciation of some words vary in English is not that surprising. Other English dictionaries have the same meaning but only give the pronunciation with long "e". This includes BE dictionaries (which mark its usage as "US" or similar):
Having a sickly appearance: You're looking a little peaked today.
[The American Heritage Dictionary of the English Language]
thin and drawn, or weak and wan, as from illness
Origin of peaked
[Webster's New World College Dictionary, Fifth Edition]
- pale and drawn in appearance so as to suggest illness or stress; wan and sickly.
[Random House Unabridged Dictionary, Copyright © 1997]
peak·ed /ˈpē,kid/ (also pe·kid)
▪ adj. (of a person) gaunt and pale from illness or fatigue: you do look a little peaked.
[New Oxford American Dictionary, Second Edition 2005]
(of a person) looking slightly ill and often pale
[Definition of peaked from the Cambridge Academic Content Dictionary © Cambridge University Press]
While Nixon looked peaked throughout the debate, Kennedy looked like a poised diplomat oozing confidence. President Kennedy captured the hearts of all Americans by his stirring inauguration speech when he said:
[Fred C. Feddeck: Hale Men of Fordham: Hail!; Trafford Publishing, 2001.]
Looking a bit peaked - Baltimore Sun
www.baltimoresun.com › sports › olympics
13.08.2008 · Maybe all this simply was too much for Katie Hoff. Talk of gold medals and a sack full of medals. Five individual events - none shorter than 200 - and a relay.
“Come on in. You look good too,” he offered generously to this man who looked peaked, undernourished, harried, and old. “Sit down, for God sakes.” The chaplain sat down submissively.
[Joseph Heller: Closing Time - The Sequel to Catch 22; Simon & Schuster, 1994]
“I certainly do. Last winter I thought she looked a little peaked, but today her color is so good. And the hair style is flattering.”
Actually, she looked quite dead and a little pale, but Grandma never seemed to notice.
[Erma Bombeck: Open Road Media; 2013
Forever, Erma: Best-Loved Writing From America's Favorite Humorist]
But when he nosed his car into the parking lot, he looked a little peaked, and asked if we could just go get a cup of coffee. Smelling of cologne, he folded himself into the passenger seat of my truck.
[Marc Smirnoff: The Oxford American Book of Great Music Writing; University of Arkansas Press, 2012]
EDIT: But did you mean “peaked” as one syllable?
My apologies to Hecuba - UK. I overlooked the fact that Hecuba was commenting on only the one-syllable forms. I meant "peaked" with two syllables.