切|せつsetsu[1]atamadaka (head-high)

1. na-adjective, nouneager; earnest; ardent; kind; keen; acute
2. interjectionOFF (on switch)also きり

• Synonym熱心ねっしんNeutralCommon everyday word for being enthusiastic and actively involved; it stresses putting energy into something, while 「切」 stresses eager, earnest feeling, as in 「切に願う」.
• Synonym本気ほんきNeutralCommon in speech; means being serious and not joking, as in 「本気で怒る」. Unlike 「切」, it is about being in earnest, not about eager, urgent feelings.
• Synonym真摯しんしWrittenWritten, formal word for a sincere, earnest attitude, as in 「真摯に受け止める」; it stresses honesty of manner rather than eager urgency.
• Synonym一途いちずNeutralMeans single-minded devotion to one thing or one person, as in 「一途な恋」; the focus is on concentration, not eager, urgent feeling.
• Synonym懸命けんめいWrittenWritten, formal word for striving with all one's effort, as in 「懸命の捜索」; it stresses full exertion rather than keen, eager feeling.
• Synonym熱誠ねっせいWrittenRare written word for warm, sincere devotion; in modern Japanese 「熱意」 is normally used instead.
• Synonym意欲的いよくてきNeutralMeans motivated and keen to take things on, as in 「意欲的な作品」; it stresses a positive, go-getting attitude rather than earnest feeling.
• Related一途いちずNeutralMeans single-minded devotion to one thing or one person, as in 「一途な恋」; the focus is on concentration, not eager, urgent feeling.
• Related一生懸命いっしょうけんめいNeutralThe most common everyday word for doing something with all one's might; it stresses going all out, not the eager, urgent feeling of 「切」.
• Related真面目まじめNeutralRefers to a serious, honest, well-behaved character; it describes personality and conduct, not a keen sense of urgency.
• Related真剣しんけんNeutralMeans serious and not half-hearted in attitude, as in 「真剣勝負」; it can also literally mean a real sword as opposed to a practice one.
• Related乗り気のりきCasualColloquial word for being interested and willing to take part, as in 「乗り気になる」; it is about enthusiasm for joining in, not earnest urgency.
• RelatedシリアスNeutralLoanword meaning grave and solemn; mostly describes the tone of stories or scenes, as in 「シリアスな展開」.
• Related一筋ひとすじNeutralMeans unwavering devotion to one thing, as in 「仕事一筋」; the stress is on single-minded focus, while 「切」 stresses eager, urgent feeling.
• RelatedひたむきNeutralMeans throwing yourself wholeheartedly into one thing, as in 「ひたむきな努力」; the stress is on single-minded, unswerving commitment.
• Related生真面目きまじめNeutralMeans overly serious and inflexible, often with a teasing nuance; it describes a rigidly earnest personality, not eager feeling.
• Related摯実しじつWrittenRare written word for sincere, earnest conduct; in modern Japanese 「真摯」 is normally used instead.

Use 「切」 for keen, eager, earnest feelings, as in 「切に願う」「切なる思い」「痛切」. For enthusiasm say 「熱心」; for being serious say 「真剣」 or 「本気」; for going all out say 「一生懸命」; for single-minded devotion say 「一途」 or 「一筋」.

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

1. （セツ）緊急きんきゅうである、余裕よゆうがない。
2. （セツ） 心こころを込こめて祈いのるさま。
3. （セツ） 身みにしみて強つよく感かんじるさま。