1. replacement, replacing

the act of furnishing an equivalent person or thing in the place of another

Example Sentences:
'replacing the star will not be easy'

• replacing

2. alternate, replacement, surrogate

someone who takes the place of another person

• alternate
• surrogate

3. permutation, replacement, substitution, switch, transposition

an event in which one thing is substituted for another

Example Sentences:
'the replacement of lost blood by a transfusion of donor blood'

• permutation
• substitution
• switch
• transposition

4. replacement, substitute

a person or thing that takes or can take the place of another

• substitute

5. refilling, renewal, replacement, replenishment

filling again by supplying what has been used up

• refilling
• renewal
• replenishment

6. replacement, successor

a person who follows next in order

Example Sentences:
'he was President Lincoln's successor'

• successor