replacement in WordNet English dictionary

1. someone who takes the place of another person
   surrogate  alternate  replacement 
   
2. an event in which one thing is substituted for another
   "the replacement of lost blood by a transfusion of donor blood"
   substitution  permutation  transposition  replacement  switch 
   
3. filling again by supplying what has been used up
   refilling  replenishment  replacement  renewal 
   
4. the act of furnishing an equivalent person or thing in the place of another
   "replacing the star will not be easy"
   replacement  replacing 
   
5. a person or thing that takes or can take the place of another
   substitute  replacement 
   
6. a person who follows next in order
   "he was President Lincoln's successor"
   successor  replacement