1. Without official authorization
   "he had made some money on the side"
   - unofficially

Encyclopedia: On the side

• case law
• case officer
• case shot
• case study
• case-by-case
• case-fatality proportion
• case-hardened
• case-hardened steel
• case-to-infection proportion
• case-to-infection ratio
• caseate
• caseation
• casebook
• cased
• caseful
• caseharden
• casein
• casein glue
• casein paint
• caseload
• casemaking clothes moth
• casemate
• casement
• casement window
• caseous