Smidgen (4)

(Other definitions for tad that I've seen before include "Small amount or degree" , "Small bit" , "(A) bit, touch" , "A small amount (colloq.)" , "Slight amount" .)

(Other definitions for bit that I've seen before include "Cutting piece of a drill (3)" , "The boring-piece of a drill" , "scrap" , "Part of 21 across" , "Took effect - fragment" .)

(Other definitions for dab that I've seen before include "Apply small amounts (usually a liquid) to a surface" , "Touch gently - fingerprint" , "Flounder" , "Expert; flat fish" , "Light stroke" .)

(Other definitions for iota that I've seen before include "A little piece" , "Tiniest scrap" , "Ninth letter of Greek alphabet, small amount" , "Greek letter; tiny amount" , "Scintilla" .)

(Other definitions for toad that I've seen before include "A loathsome person" , "Ancestral hall on River Bank" , "Wind in Willows motorist" , "driver of reckless repute" , "Warty creature" .)

(Other definitions for mite that I've seen before include "Little chap" , "The widow's small donation" , "Child; a small amount" , "The widow's contribution, just in time" , "Tiny creature found in food" .)

(Other definitions for trace that I've seen before include "Very small amount that can only just be detected" , "Find - remnant of something" , "Find; copy; small amount" , "a little bit" , "Minute quantity" .)

(Another definition for skosh that I've seen is " American scrap".)