- 第四纪 dìsìjì quaternarythe Quaternary geological period, encompassing the recent ice ages and the rise of modern humans
- 第四台 dìsìtái cable TVcable television, especially referring to the historically unlicensed and now standard cable services in Taiwan
- 第四十一 dìsìshíyī forty-firstthe ordinal number forty-first
- 第四季度 dìsìjìdù fourth quarterfourth quarter (of the financial or calendar year)
- 第四权 dìsìquán fourth estatethe fourth estate; the press
- 第四面墙 dìsìmiànqiáng fourth wallthe fourth wall (in theater, TV, film etc)
- 第四堵墙 dìsìdǔqiáng fourth wallthe fourth wall (in theater, TV, film etc)
- 第四声 dìsìshēng fourth tonethe fourth tone in Mandarin Chinese, characterized by a falling pitch
- 第四季 dìsìjì fourth quarter