A series or sequence; a connected set of events or things (as in 'a series of events').
一連の会議の後で最終決定が出た。
The final decision came after a series of meetings.
彼は一連の手続きを担当した。
He was in charge of the sequence of procedures.
事件は一連の関連した出来事だった。
The incident was a series of related events.
A (rare) unit meaning two reams (i.e., 1,000 sheets) in older usage.
大量印刷のため、一連（約1000枚）ずつ紙を用意した。
For mass printing, we prepared paper in batches of one ren (about 1,000 sheets).
A verse or stanza; a unit of a poem or sequence of lines.
その詩の一連が特に印象的だった。
One stanza of that poem was particularly striking.
古い和歌集には一連ごとに注釈が付いていることがある。
Old waka collections sometimes include annotations for each stanza.