(1)
〈美〉紧急立法;紧急法令
由于存在紧急情况而制定的法律，依其规定在其通过后、或经签署后立即生效。

(2)紧急市政条例
为维护公共安全、秩序、财产、卫生、道德等而制定的，规定在其通过后立即生效的市政〔municipal〕条例。

• old age
• Old-Age and Survivors' Insurance Act
• Old-Age and Survivors' Insurance/OASI
• old-age assistance
• old-age exemption
• old age pensions
• Old Age, Survivors, and Disability Insurance/OASDI
• Old and New Extent
• Old Bailey
• Old Booke of Entries
• Old Christmas Day
• Olde Terms de la Ley
• Old Lady Day
• Old Lammas Day
• old line company
• old line policy
• Old Martinmas
• Old Michaelmas Day
• Old Midsummer Day
• Old Natura Brevium/O.N.B.
• old rent
• old school
• old school physician
• old style calendar
• old style/O.S.