backdate means an assigned date that is earlier than the current or true date. Lexicurio rates it Sui generis — a strength score of 90 out of 100.
backdate is pronounced /bækˈdeɪt/.
Etymology
From back + date.
noun
- An assigned date that is earlier than the current or true date.“The backdates on the clearance forms made the little man's papers worthless […]”
verb
- To give or assign a date to a document that is earlier than the current or true date.