How to say "decline" in Japanese

• 下落げらくCommon
  noun, suru verb, intransitive verbDecline as a fall in price, value or market level — a slump in worth. Typical contexts are stock prices, land values or currency losing value.
  株式市場かぶしきしじょうは今日きょう、下落げらくした。↗

  The stock market has dropped today.
• 減少げんしょうJLPT N1approx.Common
  suru verb, transitive verb, intransitive verb, no-adjectiveDecline in the sense of a decrease in number, amount or quantity — population, sales or resources becoming fewer or smaller. It counts what shrinks rather than judging quality.
  あまりチームに頼たよりすぎると、個人こじんの闘争とうそう本能ほんのうが減少げんしょうするかもしれない。↗

  When you rely on the team too much, it may reduce your individual competitive instincts.
• 低下ていかJLPT N2approx.Common
  noun, suru verb, intransitive verbDecline as a drop in level, standard, quality or ability — grades, efficiency, performance or morale sinking below a former level; it can shade into deterioration.
  たしかに出生率しゅっしょうりつの低下ていかで子供こどもの数かずが減へり、学校がっこうでも生徒せいとの数かずが少すくなくなっているのは事実じじつですが、しかし、これはまったくもってけっこうなことです。↗

  It's true that there are fewer children due to the falling birthrate, and there are fewer children in the school, but that is all to the good.
• 衰退すいたいCommon
  noun, suru verb, intransitive verbDecline as gradual weakening, waning or decay — the ebbing of vitality, prosperity, memory or an industry over time. It suggests something once strong slowly losing its force.
  ４７５年ねんはローマ帝国ていこくの「衰退すいたい」を示しめす年としではあっても、「滅亡めつぼう」を意味いみする年としではありません。↗

  Although 475AD is the year that shows the 'decline' of the Roman Empire, it is not the year of its 'fall'.
• さがりCommon
  nounThe noun from the verb for going down: chiefly physical lowering or hanging down of things. For abstract senses of decline it is seldom the word you want.

Choose by what is declining: 下落 for prices and values, 減少 for quantities and numbers, 低下 for levels, standards or ability, 衰退 for gradual weakening or decay, while 「さがり」 is mainly physical lowering.

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

• 下落げらくdepreciation
• 減少げんしょうdecrease
• 低下ていかfall
• 衰退すいたいdecline
• さがりfall
• 衰えるおとろえるto become weak
• 拒むこばむto refuse
• 減退げんたいdecline
• 衰えおとろえweakening
• 漸減ぜんげんgradual decrease
• 低落ていらくfall
• 断ることわるto refuse
• 弱るよわるto weaken
• 下降かこうdescent
• 否むいなむto refuse
• 落ち込みおちこみdecline
• 寂れるさびれるto decline (in prosperity)
• 凋落ちょうらくdecline
• 下押すしたおすto decline (stock market)
• 衰微すいびdecline
• 退勢たいせいdecline
• 衰滅すいめつdecline
• 萎靡いびdecline
• 衰幣すいへいdecline
• 堕ちるおちるto decline (of morals, character, etc.)
• 下押ししたおしfall
• レベルダウンdecrease in level
• 下坂しもさかdownhill
• 衰勢すいせいdownward tendency
• 廃残はいざんdown-and-out
• 落潮らくちょうlow tide
• 頽唐たいとうdecadence
• 反動減はんどうげんdownturn (as a reaction to some event)
• 退廃たいはい(moral) decay
• 廃退はいたい(moral) decay
• 謝るあやまるto refuse
• 傾くかたむくto decline
• 下り坂くだりざかdecline
• 砕けるくだけるto collapse
• 落ちるおちるto decrease (of popularity, quality, speed, sales, etc.)
• 斜陽しゃようdecline (e.g. of industry)
• 敗残はいざんdecline (of a person, business, etc.)
• 辞すじすto decline
• 冷え込むひえこむto worsen (of relations, economic conditions, etc.)
• 失速しっそくdownturn
• 廃れるすたれるto decline (e.g. of morals)
• 辞するじするto decline
• 黄昏れるたそがれるto decline (after a peak)
• 下火になるしたびになるto decline
• 移ろううつろうto fade
• 冷え込みひえこみcooling down (of economic activity)
• 傾ぐかしぐto go down (sun)
• 下向きしたむき(market) decline
• 崩れるくずれるto crash (stock market)