Unspent Transaction Output, UTXO

This definition comes from the technical glossary.

Definition

An Unspent Transaction Output (UTXO) that can be spent as an input in a new transaction.

Synonyms

UTXO

Not To Be Confused With

Output (any output, whether spent or not. Outputs are a superset of UTXOs)

Links

UTXO — Bitcoin.org Developer Guide
How big is the UTXO database? — Bitcoin StackExchange