Other forms: unraveling, unraveled, unravels, unravelling, unravelled
To unravel is to come apart thread by thread. The jumper unravelled, unravel the mystery, everything unravelled.
Literally it is what knitting does when a stitch is dropped — one thread pulls out and the whole thing follows, which is exactly the image the figurative use needs. Of a plan or a life it means falling apart gradually rather than at once. Of a mystery it means the opposite: unravelling it is solving it. Note that ravel means the same thing as unravel, which is a genuine oddity of English.
1verbunravelTo come apart thread by thread.
“The sleeve of my old jumper started to unravel when I pulled a loose thread.”
2verbsolveTo solve something complicated.
“The detective slowly unravelled the mystery of the missing painting.”
unravel is a coming apart.
unRAVEL → it comes apart while you TRAVEL
Pull one loose thread at the end of the sleeve and the whole thing comes apart in your hands while you travel home on the bus.
hooks ontotravel
Un- plus ravel, from a Dutch word meaning to fray. Ravel means both to tangle and to untangle, so unravel is either a redundancy or a clarification, depending on which sense you start from.
Proto-Indo-European
*h₂énti
English, today
unravel
From un- + ravel. 2
Etymology from Wiktionary, CC BY-SA
Practised in Sharper Verbs, Cutting & Breaking