| 系列 | けいれつ | series, sequence, system, order of succession; keiretsu (conglomeration of businesses linked by cross-shareholdings) |
| 日系 | にっけい | (of) Japanese descent |
| 系 | けい | system, lineage, group; corollary; (geological) system (range of strata that correspond to a particular time period); (taxonomical) series |
| 体系 | たいけい | system, organization, organisation, architecture |
| 生態系 | せいたいけい | ecosystem |
| 系統 | けいとう | system, family line, geological formation, lineage, ancestry |
| 直系 | ちょっけい | direct descent, direct line |
| 水系 | すいけい | drainage system |
| 家系 | かけい | family lineage |
| 系譜 | けいふ | genealogy, pedigree |
