Trace calls in it, improperly (9)
I believe the answer is:
scintilla
'trace' is the definition.
(both can mean a small amount)
'calls in it improperly' is the wordplay.
'improperly' is an anagram indicator (I've seen this in other clues).
'calls'+'in'+'it'='callsinit'
'callsinit' is an anagram of 'SCINTILLA'.
(Other definitions for scintilla that I've seen before include "Tiny trace or amount" , "A tiny bit" , "A spark; a trace" , "The smallest amount" , "Tiniest bit" .)