循環|じゅんかんjunkan[0]heiban (flat)

1. noun, suru verb, intransitive verbcirculation; rotation; cycle; loop
   血液けつえきは体内たいないを循環じゅんかんする。↗

   Blood circulates through the body.

• SynonymめぐるNeutralA verb for things going or coming round, as in 「季節が巡る」; it carries a literary tinge, while 「循環」 is a Sino-Japanese noun.
• Synonym回るまわるNeutralAnother spelling of 「巡る」 (still read めぐる), used of blood and money circulating, as in 「血が巡る」「お金が巡る」; close to the circulation sense of 「循環」 but more colloquial.
• Synonym回りまわりNeutralA turn around or one's surroundings, as in 「身の回り」; it leans toward rotation and the surrounding area.
• SynonymサイクルNeutralA loanword for a cycle or period, as in 「ライフサイクル」; it points to the repeating cycle itself rather than the flow.
• Synonym巡りめぐりNeutralCirculation or touring, as in 「血の巡り」「名所巡り」; it leans toward making a round rather than ongoing circulation.
• Related巡回じゅんかいNeutralGoing around on a round or patrol, as in 「巡回バス」; it means visiting places in turn along a route, not a repeating cycle.
• Related周期しゅうきNeutralA period or time cycle, as in 「周期的に」; it stresses the interval between repetitions and does not refer to flow.
• Related回転かいてんNeutralRotation or turnover, as in 「頭の回転が速い」; it centers on spinning about an axis rather than circulating.
• Related旋回せんかいWrittenA written word for circling or turning, as in 「飛行機が旋回する」; used mainly of aircraft and ships.
• Related自転じてんWrittenA written word for spinning on one's own axis, often of celestial bodies, as in 「地球の自転」; 「循環」 is about recurring flow.
• Related転回てんかいWrittenA written word for turning or reversing, as in 「方針を転回する」; it centers on a change of direction.
• Related回旋かいせんWrittenA written word for whirling or circling; used mostly in music and flight contexts, and examples are scarce.
• Related回転運動かいてんうんどうWrittenA written term for rotational motion in physics; strictly a specialist term.
• Related公転こうてんWrittenA written astronomy term for one celestial body orbiting another, such as the Earth going around the Sun.

Use 「循環」 for things flowing round and round or repeating, as in 「血液循環」 and 「悪循環」; the verb 「循環する」 works too. For a repeating period choose 「サイクル」 or 「周期」, for spinning choose 「回転」, and for the native verb of going round use 「巡る」. The rest cover narrower senses: rounds and patrols (「巡回」), circling by planes and ships (「旋回」), and technical rotation terms (「自転」「公転」).

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

1. ある閉とじた系けいにおいて、物事ものごとが巡めぐり続つづけること。
2. 同おなじような物事ものごとが、同おなじような順序じゅんじょで繰り返くりかえされること。