(not) at all; (not) in the least; (none) whatsoever
Used with a negative verb to emphasize complete absence or denial. Stronger than 全然.
I don't think that at all.
I have absolutely no intention of meeting him.
Rare kanji spelling; easily confused with 更に (さらに).
Rare kanji spelling; easily confused with 更に (さらに).
Reduplication of 更 (さら), an old word meaning 'again' or 'more', with the reduplication intensifying the negative sense to 'not even a bit more'. The exact historical development is uncertain.