A mechanism for miners to signal readiness for soft-fork upgrades using bits in the block version field (BIP9).
Version bits (BIP9) repurpose the block version field for activation signaling. If sufficient signaling is observed within a window, the new rules lock-in for activation.
"Miners set a specific bit in block versions to indicate support for SegWit; once the threshold was met over a period, the upgrade locked in."
All terms and definitions may update as the Cryptionary improves.