A small amount of money lost in the gross (10)
I believe the answer is:
shoestring
'a small amount of money' is the definition.
I can't judge whether this definition defines the answer.
'lost in the gross' is the wordplay.
'lost' indicates anagramming the letters.
'in'+'the'+'gross'='inthegross'
'inthegross' is an anagram of 'SHOESTRING'.
Can you help me to learn more?
(Other definitions for shoestring that I've seen before include "A minimum of money" , "Minimal amount of money" , "for securing a trainer?" , "Barely sufficient funds" , "Very little money" .)