Txid, Transaction Identifier

This definition comes from the technical glossary.

Definition

An identifier used to uniquely identify a particular transaction; specifically, the sha256d hash of the transaction.

Synonyms

Txid

Not To Be Confused With

Outpoint (the combination of a txid with a vout used to identify a specific output)

Links

Txid — Bitcoin.org Developer Guide
How do I calculate the txid of this raw transaction? — Bitcoin StackExchange