1.
absolutely not; by no means (with a negative)
Used with a negative predicate to deny something flatly and with conviction. This is by far the more common pattern.
2.
absolutely; without fail; come what may (with an affirmative)
Used with an affirmative predicate to declare firm resolve. Formal and emphatic, common in speeches and written declarations.
The te-form of the classical 断ずる (to decide, to judge), fossilized as an adverb. Formal and emphatic; in casual speech 絶対 does the same work.
Common collocations
- 断じて許さない: will absolutely not tolerate
- 断じて認めない: absolutely refuse to acknowledge
- 断じてない: absolutely not so
- 断じて行う: to act with full resolve