noun, noun which may take the genitive case particle 'no'
fully populated; fully implemented
Computing term describing a system, database, or component that has all intended features, data, or modules present and active.
This test environment uses a fully populated database.
It's difficult to go into production without a fully implemented system.
実装 means 'implementation' or 'mounting' in a general sense; 完全実装 specifies that the implementation is complete or fully populated.
Compound of 完全 (complete) and 実装 (implementation). A straightforward technical term with no obscure historical derivation.