Least, slightest (7)
I believe the answer is:
minimal
This clue is a double definition.
'least' is the first definition.
(similar in meaning)
'slightest' is the second definition.
(thesaurus)
(Other definitions for minimal that I've seen before include "Least possible; negligible" , "Of a smallest amount" , "Very little" , "barely worth considering" , "Token" .)