How to say "senior" in Japanese

• 先輩せんぱいJLPT N4approx.Common
  noun, suffixCovers the relational sense of 'senior' — a person ahead of you at school or in a company, such as an older student or a colleague who joined earlier; it implies a senior–junior relationship.
  私わたしたちは彼かれをよき先輩せんぱいとして尊敬そんけいしている。↗

  We respect him as a good senior.
• シニアCommon
  nounThe loanword, used mainly for older adults as an age group — senior citizens and age-based categories — rather than for an individual senior colleague; for a school or workplace senior, 先輩 is the word.
• 年長ねんちょうJLPT N1approx.Common
  no-adjective, na-adjectiveDescribes being older in age relative to others in a group, rather than holding a senior position; it does not carry the 先輩 sense of a senior at school or work.
  年長ねんちょうの息子むすこたちは今いまは父親ちちおやからまったく独立どくりつしている。↗

  The elder sons are now quite independent of their father.
• 古参こさんCommon
  no-adjectiveA veteran or old-timer: someone whose seniority comes from long membership in an organization, community, or fandom, as opposed to newcomers; it is about length of involvement, not age.
  古参こさん議員ぎいんたちは、選挙せんきょで参議院さんぎいんの議席ぎせきを失うしないそうになりました。↗

  The old guard was nearly voted out of the Upper House.
• 年上としうえCommon
  no-adjectiveRefers simply to someone older than you in age; it states an age difference and implies no school or workplace hierarchy, unlike 先輩.
  トムは私より２つ年上としうえである。↗

  Tom is two years senior to me.

Choose 先輩 for a senior at school or work, 年上 for someone simply older than you, 年長 for the older members of a group, 「シニア」 for older adults as an age group, and 古参 for a long-standing veteran.

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

• 先輩せんぱいsenior (at school, work, etc.)
• シニアsenior
• 年長ねんちょうsenior
• 古参こさんsenior
• 年上としうえolder
• 長老ちょうろうelder
• 目上めうえsuperior
• 上役うわやくone's superior
• 年嵩としかさsenior
• 古参者こさんしゃsenior
• 年長者ねんちょうしゃsenior
• 最上級生さいじょうきゅうせいsenior (e.g. at school)
• ぱいせんsenior (at work or school)
• エルダーelder
• 上長じょうちょうone's superior
• 古株ふるかぶold-timer
• 位の高いくらいのたかいhigh-ranking
• 四回生よんかいせいfourth year (college) student
• 丈人じょうじんelder
• 老ろうold age
• 大おおolder
• 高級こうきゅうhigh-ranking
• 先進せんしんseniority
• 年配ねんぱいolder (than)
• 大きおおきgreater (of equal court ranks)
• 上うえelder