How to say "utmost" in Japanese

• 最善さいぜんJLPT N1approx.Common
  no-adjectiveCovers 'utmost' in the sense of the very best — as in doing one's utmost, the best effort or course of action available. It frames 'utmost' as a superlative of quality rather than of degree.
  それが私わたしたちが今いまできる最善さいぜんの方法ほうほうだ。↗

  That's the best way we can do now.
• 全幅ぜんぷくCommon
  no-adjectiveCovers 'utmost' meaning full or wholehearted, typically expressing the entire extent of one's trust, support, or energy. It emphasizes devoting or according something completely, without reservation.
  彼かれらは指導者しどうしゃに全幅ぜんぷくの信頼しんらいをおいている。↗

  They have full confidence in their leader.
• 極度きょくどCommon
  no-adjective, na-adjectiveCovers 'utmost' as maximum or extreme degree, describing states such as extreme tension, fatigue, or caution. It is a poor choice for 'do one's utmost' — that sense really calls for another word.
  人間にんげんも極度きょくどに寒さむい温度おんどに対たいしては、防御ぼうぎょ装置そうちを備そなえている。↗

  Man, too, has been given protective devices against extreme temperatures.

Choose 最善 for 'utmost' as the best possible effort or result, 全幅 for wholehearted commitment of feeling or energy, and 極度 for extreme or maximum degree, especially of tension or caution.

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

• 最善さいぜんthe very best
• 全幅ぜんぷくfull
• 極度きょくどmaximum