How to say "fully" in Japanese

• しみじみJLPT N2approx.Common
  adverb (with と)Covers 'fully' only in the sense of feeling or realizing something keenly and deeply; it is not about quantity or completeness, so it seldom translates neutral 'fully'.
  その悲かなしい話はなしは彼女かのじょにしみじみと感かんじられた。↗

  The sad story came home to her.
• たっぷりJLPT N3approx.Common
  adverb (with と), na-adjective, suffixCovers 'fully' when it means 'to the full' in quantity — amply, generously, with plenty to spare, as in sleeping fully or having ample time; not about emotions or sufficiency.
  教授きょうじゅの話はなしはユーモアたっぷりだった。↗

  The professor's speech was full of humor.
• 優にゆうにCommon
  adverbCovers 'fully' before amounts and degrees that comfortably reach or exceed a level — 'fully ten years', 'well over a hundred'; the sense is 'easily, with room to spare'.
  ここから郵便局ゆうびんきょくまではゆうに５キロあります。↗

  The post office is a good five kilometers away from here.
• 十分じゅうぶんJLPT N4approx.Common
  adverbThe all-purpose choice: use it whenever 'fully' simply means 'sufficiently, thoroughly, enough' — fully understanding, fully prepared, fully satisfied; when in doubt, this is the word to reach for.
  「もっと召し上めしあがりますか」「いいえ、じゅうぶんいただきました」↗

  "Would you like any more?" "No, I've had enough."
• がっつりCommon
  adverb (with と)Colloquial and rarely the neutral word for 'fully': it means doing something properly and heartily, taking a solid, satisfying amount — the tone of tucking into a big meal.

Choose 十分 for the neutral sense 'sufficiently, fully'; 「たっぷり」 for generous quantity, 「優に」 for amounts that comfortably exceed a level, 「しみじみ」 for deeply felt realization, and 「がっつり」 for casual, hearty fullness.

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

• しみじみkeenly
• たっぷりplentifully
• 優にゆうにeasily (reach, exceed, etc.)
• ふっくらfully
• ふっくりfully
• 全幅的ぜんぷくてきfully
• 余すところなくあますところなくfully
• 遺憾なくいかんなくfully
• フルにfully
• 余すことなくあますことなくfully
• とくとcarefully
• とっぷりcompletely
• 万々まんまんvery much
• ふんなんにin plenty
• 詳しくくわしくin detail
• １００パーひゃくパー100 percent
• みっちりintensely
• つぶさにin detail
• とっくりthoroughly
• 存分にぞんぶんにto one's heart's content
• ふんだんにabundantly
• 十分じゅうぶんsufficiently
• がんがんfully
• がっつりproperly
• しっかりproperly
• いちいちevery single
• 重々じゅうじゅうfully (e.g. understand)
• みっしりfully
• とことんto the very end
• いっぱいfully