also: ぜっきょ · ぜっゆる
expression
absolutely unforgivable; completely inexcusable
Internet slang abbreviation of 絶対に許さない. Used in online arguments, social media, and gaming to express strong condemnation.
あの人の発言、絶許だわ。
That person's remark is absolutely unforgivable.
チート使うとか絶許。
Using cheats is completely inexcusable.
The full phrase from which 絶許 is abbreviated. 絶許 is much more casual and internet-specific.
Abbreviation of 絶対に許さない (zettai ni yurusanai, 'absolutely will not forgive'). The exact derivation is uncertain, but it likely arose in online communities.