1. Being in effect or operation
   "bus service is in operation during the emergency"
   - operational, operating

See also: operative

• representative sample
• representative sampling
• represented
• representer
• repress
• repressed
• represser
• repressible
• repressing
• repression
• repressive
• repressiveness
• repressor
• repressor gene
• superlative degree
• superlatively
• superload
• superlunar
• superlunary
• superman
• supermarket
• supermarketeer
• supermarketer
• Supermex
• supermodel