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1. To a proportionate degree
   "your salary will rise proportionately to your workload";
   - proportionally
    
2. In a way that is in correspondence among the constituents of another entity
   "the height of this wall must be reduced proportionately to give the room pleasant dimensions"
    
3. In a way that agrees in amount, magnitude or degree
   - pro rata

Antonym: disproportionately