Definitions:

1. Describes something that has been made or done four times, or exists in four identical copies. ADJECTIVE
   • He received quadruplicate copies of the report to distribute to the team.
2. Means to multiply or make four identical copies of something. VERB
   • The documents were quadruplicated to ensure each department had a copy.
3. Refers to one of four identical copies of a document, object, or form. NOUN
   • The legal agreement was signed in quadruplicate, with one copy for each party involved.

Synonyms:

• four
• fourfold
• quadruple