unravel
To come apart slowly into separate pieces or threads.
When something unravels, it comes apart strand by strand, like a sweater that starts losing its threads or a rope that separates into individual fibers. If you pull the wrong thread on a knitted scarf, you might watch it unravel before your eyes, the careful pattern dissolving into loose yarn.
The word also describes how plans, situations, or understanding can fall apart. A mystery unravels when a detective figures it out piece by piece, revealing the truth hidden beneath. A complicated lie might unravel when one person notices a small inconsistency, then another, until the whole story falls apart. When scientists unravel the secrets of DNA, they're carefully working out how something complex actually works.
You might hear someone say their day unraveled after one thing went wrong, then another, and another, until nothing went as planned. The word captures both the slow, steady way things can come apart and the sense that once the process starts, it's hard to stop. Think of trying to stop a ball of yarn from rolling down stairs, trailing thread behind it. That's the feeling of something unraveling.