世紀【せいき】
century, era, of the century (e.g. fight of the century)
紀行【きこう】
traveller's journal, traveler's journal, travelogue
紀元前【きげんぜん】
pre-era, BC, BCE
紀元【きげん】
era, CE (Common Era), AD (Anno Domini)
綱紀【こうき】
law and order, (official) discipline
風紀【ふうき】
public morals, discipline, rules governing social behavior