第四纪

Traditional form:

第四紀

Pinyin (reading):

dìsìjì

Definitions:

• fourth period
• quaternary (geological period covering the recent ice ages over the last 180,000 years)

Characters:

• 第 - sequence, number; grade, degree; particle prefacing an ordinal
• 四 - four
• 纪 - discipline, age; period, era; record, annal

Traditional characters:

• 第 - sequence, number; grade, degree; particle prefacing an ordinal
• 四 - four
• 紀 - discipline, age; period, era; record, annal