EXAMPLES FROM THE WEB FOR RIDDLE
The sphinx did not slay herself until her riddle had been guessed.
Percy Roden was gratified, and read the riddle by the light of his own vanity.
"He hasn't got a father," I replied, hoping for some answer as to a riddle.
I had enough of it, and went out, firmly resolved to find the key to the riddle.
All questioning was vain; her heart gave no solution of the riddle.
After having read it, she assured me that this script was a riddle to her.
Fandor realised that, in this instance, the riddle of sex was still unsolved.
Juve now knew the answer to the riddle of the bandit's disappearance.
Scientific men were appealed to, to help solve the riddle, but were helpless.
This, however, like a prophet he expresses in a sort of riddle, for 'Know thyself!'
WORD ORIGIN
"A word game or joke, comprising a question or statement couched in deliberately puzzling terms, propounded for solving by the hearer/reader using clues embedded within that wording" [Oxford Dictionary of English Folklore], early 13c., from Old English rædels "riddle; counsel; conjecture; imagination; discussion," common Germanic (cf. Old Frisian riedsal "riddle," Old Saxon radisli, Middle Dutch raetsel, Dutch raadsel, Old High German radisle, German Rätsel "riddle").
The first element is from Proto-Germanic *redaz-, from PIE *re-dh-, from PIE *re(1)- "to reason, count" (cf. Old English rædan "to advise, counsel, read, guess;" see read (v.)). The ending is Old English noun suffix -els, the -s of which later was mistaken for a plural affix and stripped off. Meaning "anything which puzzles or perplexes" is from late 14c.