Not engaged in an assigned task, duty or occupation.

(historical) A tax formerly paid on all chimneys in England.

Exempt from duty, especially from customs duty.

A duty-free article, especially part of the allowance of such goods allowed to be imported. / A shop where duty-free goods can be bought.

(military) A period of time spent on a specific assignment, especially on an overseas mission.

A period of time during which a person is obliged to be a member of a panel of people who may be called as members of one or more juries.

(law, idiomatic) A duty prescribed by the law, to act or forbear from acting.

(economics) A tax levied upon certain documents, a stamp being applied to show that tax has been paid. / (UK) Ellipsis of stamp duty land tax, a tax on land transactions in England and Northern Ireland.

Designed to withstand hard usage without breaking.

An inheritance tax or estate tax.