1. Productive relative to the cost
   - cost-effective

See also: efficient

• Ritalin
• ritardando
• rite
• rite of passage
• ritenuto
• ritonavir
• ritornello
• Rittenhouse
• ritual
• ritual dance
• ritual dancing
• ritual killing
• ritualise
• ritualism
• ritualist
• ritualistic
• ritualistically
• ritualize
• ritually
• ritz
• ritzy
• rival
• rivalrous
• rivalry
• rive