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1. A gradual decrease in magnitude or extent
   "the waning of his enthusiasm was obvious"; "the waxing and waning of the moon"

1. (of the Moon) pertaining to the period during which the visible surface of the moon decreases
   "after full moon comes the waning moon"

1. Grow smaller
   "Interest in the project waned";
   - decline, go down
    
2. Become smaller
   "Interest in his novels waned"
    
3. Decrease in phase
   "the moon is waning"

Type of: decrease, diminish, drop-off, fall, lessen, lessening

Antonym: wax, waxing

Encyclopedia: Waning