Contracted constructor will harm (3)
I believe the answer is:
ill
'harm' is the definition.
(I've seen this before)
'contracted constructor will' is the wordplay.
'ILL' is hidden within the letters.
But, I'm uncertain how this is indicated.
Can you help me to learn more?
(Other definitions for ill that I've seen before include "weak" , "Out of sorts" , "In a bad way" , "'Never speak . . . of the dead'" , "Not in good health" .)