"i Haven't the __ Idea"; Slightest, Least Visible
This page is the CodyCross answer for the clue below from TV Station, Group 604, Puzzle 2 (Paid Subscription).
Question is: "i Haven't the __ Idea"; Slightest, Least Visible
and the answer is: FAINTEST
Word Meaning:
FAINTEST — superlative form of faint: most faint
Definitions from Wiktionary.