defi
n. countablen. a system of financial services — lending, borrowing, and trading — built on blockchains that run through code instead of banks or other traditional middlemen.
n. decentralized finance: an umbrella term for peer-to-peer financial services delivered through smart contracts on a blockchain, without centralized intermediaries such as banks or brokerages.
He earns interest on his savings through DeFi.
Instead of using a bank, she borrowed stablecoins through a DeFi lending protocol.
Because DeFi platforms replace intermediaries with open-source smart contracts, a single coding flaw can drain millions from a liquidity pool in seconds.
Shortened from decentralized finance, the capitalised Fi echoing forms like WiFi and SciFi.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Last updated July 19, 2026