PRI: Personal Record Identifier (Canada) PRI: Periodic Reinvestigation: PRI: Preliminary Rifle Instruction: PRI: Planning, Review, and Inspection: PRI: Progressive Routing Indicator (US DoD) PRI: Prisoner Reentry Initiative (various locations) PRI: Policy Research Institute (various locations)
Adding definition, to unite or join so as to increase the number, quantity, size, or importance: to add two cups of sugar; to add a postscript to her letter; to add insult to injury. See more. Dictionary.com
add-on therapy. Any treatment given to bolster or enhance the effectiveness of a previous one, esp. when the first treatment proved not to be fully effective.