Minute amount
'minute amount' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for iota that I've seen before include "Jot or tittle" , "Contrivance" , "letter from Greece" , "Gr. letter; small amount" , "Greek letter - small quantity" .)
(Other definitions for atom that I've seen before include "A mighty particle, makes huge explosion" , "tiny thing" , "Piece of matter in moat" , "Particle of matter now divided" , "It was once thought to be smallest particle of matter" .)
'minute amount' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for drib that I've seen before include "Steal as before" , "drop" , "A little" , "Able to be raised" , "Drab companion" .)
'minute amount' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for scintilla that I've seen before include "scrap!" , "Tiny hint, trace" , "Slight amount" , "suspicion" , "A tiny bit" .)