Is “Riddle” a Scrabble word?
Yes
RIDDLE
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Riddle
/ˈɹɪdəl/
noun
1.A verbal puzzle, mystery, or other problem of an intellectual nature.
“Here's a riddle: It's black, and white, and red all over. What is it?”
2.An ancient verbal, poetic, or literary form, in which, rather than a rhyme scheme, there are parallel opposing expressions with a hidden meaning.
Synonyms: brain-teaser, conundrum, enigma
verb
1.To speak ambiguously or enigmatically.
2.To solve, answer, or explicate a riddle or question.
“Riddle me this.”