序次 is read as じょじ (joji) and means order.
じょじ
joji
じじょ
order
ついで
successor
じょぶん
preface
じょきょく
overture
じょせつ
introduction
じょまく
curtain-raiser
じょばん
opening (in a game of go, chess, etc.)
じょれつ
rank
じょにだん
jonidan (second lowest) division
じょのくち
lowest division in sumo
じょしょう
beginning
じょにだんかく
referee officiating the second lowest division