The word 'unravel' presents a fascinating case of a word borrowing and then developing a contradictory meaning. Its core, 'ravel', entered English in the late 16th century from the Dutch 'ravelen', meaning to tangle or fray. The Old English prefix 'un-', signifying reversal, was then attached, creating a verb whose literal action is to reverse a tangle—to untangle. Intriguingly, 'ravel' itself came to also mean 'to untangle', making 'unravel' and 'ravel' synonyms in one of their senses. The modern abstract meaning, "to solve a mystery," is a logical metaphorical extension from the physical act of disentangling a knotted thread to clarifying a complex situation.

Structure: un (reversal) + ravel (to tangle) + ed (past tense suffix) un: A prefix of Germanic origin, indicating reversal or deprivation. ravel: A verb of Dutch origin (ravelen), meaning to tangle or become entangled. ed: A suffix of Old English origin, used to form the past tense and past participle of regular verbs.