[けい, kei] (n, n-suf) (1) system; lineage; group; (2) { math } corollary; (3) (geological) system (range of strata that correspond to a particular time period); (4) (taxonomical) series; (P)#222
[けいれつ, keiretsu] (n) (1) series; sequence; system; order of succession; (2) keiretsu (conglomeration of businesses linked by cross-shareholdings); (P)#1068