absolutely not; not at all
Rare emphatic negative adverb, similar to 根っから. Used before a negative verb to mean 'not in the slightest' or 'not from the very root'. The kanji spelling is literary and seldom seen.
See also: 根っから
I can't believe a word he says, not at all.
Literally 'from root to leaf', an emphatic expression meaning 'from the very foundation'. The exact origin is uncertain, but it likely developed as an intensified version of 根っから.