Winos that regularly scrap (4)
I believe the answer is:
iota
'scrap' is the definition.
(both can mean a very small amount)
'winos that regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'winos'+'that'='winosthat'
The alternating letters of 'winosthat' are 'IOTA'.
(Other definitions for iota that I've seen before include "Tiny piece" , "Greek letter - small quantity" , "Ninth Greek character" , "Grain" , "letter from Greece" .)