Correct spelling for the English word "riddel" is [ɹˈɪdə͡l], [ɹˈɪdəl], [ɹ_ˈɪ_d_əl] (IPA phonetic alphabet).
The word "riddel" is derived from the Middle English term "redel" or "ridel", which can be traced back to the Old English word "rǣdels". It ultimately finds its roots in the Germanic language family, where similar words existed in Old High German, Old Norse, and Old Saxon. The Old English word "rǣdels" initially had a broader meaning of "a piece of advice" or "a saying", but over time, it evolved to specifically refer to a challenging or puzzling question, which we now understand as a riddle.