There are six words that satisfy the following six definitions (one word for each definition) and these words share an unusual property. What are the six words and what is the unusual property?
Removed the withered heads of flowers
One who can recall an event
Emphasizes again
Calmness
Bare-armed
Whispers
The required six words are:
--> Deadheaded
--> Rememberer
--> Restresses
--> Sereneness
--> Sleeveless
--> Sussurruses
Each of the words is constituted by precisely four distinct letters with one letter having multiplicity 1, another having multiplicity 2, another having multiplicity 3 and another having multiplicity 4.