Equal in this amendment (4)
I believe the answer is:
same
'equal' is the definition.
(associated in meaning)
'in this amendment' is the wordplay.
'in' indicates a hidden word.
'SAME' can be found hidden inside 'this amendment'.
(Other definitions for same that I've seen before include "Identical, unchanged" , "Equal in amount or value" , "If - be the food of love, play on (Twelfth Night)" , "uniform" , "Ditto" .)