(いっさい)

いっさい
adverb, noun
all; entirely; (not) at all; everything
1. (not) at all; entirely; absolutely (with negative)
Used with negative expressions to mean "not at all" or "absolutely not." Emphasizes complete absence or denial.
(かれ)のことは一切(いっさい)()らない。
I don't know anything about him at all.
責任(せきにん)一切(いっさい)()いません。
We take absolutely no responsibility.
2. all; everything; the whole
Refers to everything without exception. Often used with nouns to mean "all of something."
費用(ひよう)一切(いっさい)会社(かいしゃ)負担(ふたん)します。
The company will cover all expenses.

TWO MAIN USES:

1) WITH NEGATIVE: Emphasizes complete absence

  • 一切(いっさい)〜ない (not 〜 at all)
  • 一切(いっさい)関係(かんけい)ない (have nothing to do with)
  • 一切(いっさい)責任(せきにん)()わない (take no responsibility whatsoever)

2) AS NOUN: Everything, all

  • 一切(いっさい)費用(ひよう) (all expenses)
  • 一切(いっさい)(まか)せる (to entrust everything)
  • 一切(いっさい)合切(がっさい) (everything without exception - emphatic)

COMMON EXPRESSIONS:

  • 一切(いっさい)(ことわ)りします (We refuse absolutely)
  • 一切(いっさい)ノーコメント (No comment at all)

LEGAL/BUSINESS USAGE:
一切(いっさい) is commonly used in disclaimers, contracts, and formal notices to express absolute terms.

ORIGIN:
From Buddhist terminology meaning "all things" or "everything."