退潮|たいちょうtaichou[0]heiban (flat)

1. noun, suru verb, intransitive verbebb tide; waning fortunes

• Synonym衰退すいたいNeutralMeans decline or decay, as in 「産業の衰退」; the most common word for waning fortunes.
• Synonym衰えおとろえNeutralA native word for the weakening of strength, ability or momentum, as in 「体力の衰え」 or 「勢いの衰え」; more colloquial than 「退潮」.
• Related低下ていかNeutralRefers to a drop in degree or numerical level, as in 「能力の低下」; very common, but unlike 「退潮」 it carries no image of ebbing power.
• Related下落げらくNeutralCovers falls in prices, market rates or rank; the focus is on value, and unlike 「退潮」 it does not speak of waning power.
• Related減退げんたいNeutralDescribes strength, appetite and the like weakening; the focus is on failing function, as in 「食欲減退」.
• Related減少げんしょうNeutralMeans a decrease in quantity; neutral and objective, focused on numbers, with no nuance of waning fortunes.
• Related後退こうたいNeutralMeans moving back or retreating, and also economic recession as in 「景気後退」; the focus is backward movement, not tides.
• Related低落ていらくNeutralUsed for drops in prices, popularity or reputation; the nuance is value or standing slipping away.
• Related減るへるCasualA colloquial verb for numbers or amounts getting smaller; the everyday default for decrease, focused on quantity.
• Related低減ていげんNeutralCovers lowering costs, risks and the like, as in 「コスト低減」; usually implies deliberate, active reduction.
• RelatedさがるNeutralA verb for positions or figures dropping, or for stepping back; colloquial and the most widely applicable of these words.
• Related減衰げんすいNeutralA science and engineering term for signals, vibrations and the like gradually dying away; the focus is progressive weakening.
• Related退勢たいせいWrittenA written word for a declining tide of power; close to 「退潮」 but focused on the state of a situation sliding downhill.
• Related衰勢すいせいWrittenA written word for a downward trend of fortunes; rare, and close in sense to 「退勢」.
• Related衰微すいびWrittenWritten style for something once flourishing falling into decay; it stresses the slide from prosperity to decline.
• Related減ずるげんずるWrittenA written-style verb meaning to decrease, lessen or deduct; formal and not often used.
• Antonym満潮まんちょうNeutralThe antonym: high tide, when the sea reaches its peak; the direct opposite of the ebbing 「退潮」.
• Antonym漲潮WrittenThe antonym for a rising tide; it contrasts with the ebbing 「退潮」 but is rare and literary.

「退潮」 covers an ebbing tide and, figuratively, waning power, as in 「人気が退潮する」. For decline in general 「衰退」 is the everyday default and 「衰え」 the native, more colloquial noun; 「衰微」 is the written word for a fall from past glory, and 「退勢」/「衰勢」 formal words for a declining trend. For drops in level or value use 「低下」, 「下落」 or 「低落」; for failing function 「減退」; for shrinking numbers 「減少」 or colloquial 「減る」; for cuts 「低減」; for retreat or recession 「後退」; for technical weakening 「減衰」. Antonyms: 「満潮」, rarely 「漲潮」.

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

1. 潮しおが引ひくこと。干潮かんちょう。
2. 勢力せいりょくが衰おとろえること。