必須|ひっすhissu[0]heiban (flat)

1. no-adjective, na-adjectiveindispensable; essential; requisite; required; compulsory; necessary
   堪能たんのうな英語力えいごりょくは必須ひっすです。↗

   Fluency in English is a must.

• Synonym必要ひつようNeutralNeutral and by far the broadest word for 'needed'. 「必須」 stresses that something is absolutely indispensable, as in 「必須科目」.
• Synonym不可欠ふかけつWrittenWritten style for 'indispensable', as in 「成功に不可欠だ」. 「必須」 also forms 「必須条件」 and the predicate 「必須だ」.
• Synonym必需ひつじゅWrittenWritten word for absolutely needed, as in 「生活必需品」「必需の物資」. 「必須」 leans toward required conditions.
• Synonym義務的ぎむてきWrittenWritten word for what rules or duties make compulsory, or what one does grudgingly out of obligation. 「必須」 just means necessary.
• Related肝心かんじんWrittenWritten word for what is crucial or vital, as in 「肝心なところ」. 「必須」 means something must be had.
• Related重要じゅうようNeutralNeutral word for 'important'. 「必須」 is stronger: it means something must be there and cannot be omitted.
• Related大切たいせつCasualColloquial word for important or precious. 「必須」 stresses being a must — something you cannot do without.
• Related肝要かんようWrittenWritten word for extremely important. 「必須」 leans toward must-have.
• Related枢要すうようWrittenWritten word for the pivotal point or hub of something. 「必須」 simply means must-have.
• Related切要せつようWrittenWritten word for something extremely vital or pressing. 「必須」 means must-have.
• Antonym任意にんいNeutralOptional or voluntary — left to the person's own choice. The direct opposite of 「必須」.
• Antonym省略可WrittenWritten label meaning 'may be omitted'. The opposite of 「必須」.

Use 「必須」 for what is absolutely indispensable, as in 「必須項目」 or 「生存に必須の栄養素」. For general needs choose 「必要」, for indispensable 「不可欠」, for crucial 「肝心」, and for necessities 「必需」; the opposite is 「任意」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 欠かかせないこと。必要ひつようなこと。