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

See also: operative

• material resource
• material witness
• materialisation
• materialise
• materialism
• materialist
• materialistic
• materialistically
• materiality
• materialization
• materialize
• materially
• materialness
• materials handling
• materiel
• maternal
• maternal language
• maternal quality
• maternal-infant bonding
• maternalism
• maternalistic
• maternally
• maternity
• maternity hospital
• maternity ward