plural of open problem

Alternative spelling of openwork

alert and vigilant

(informal) simple and obvious; easily decided

Taking place outdoors; alfresco

Describing a reverberatory furnace used to make steel, usually in mass-produced quantities. / Designating the steel so produced.

(architecture) Having large rooms with few dividing barriers such as partitions.

(of a sandwich) Being a single slice of bread with a topping. / Having an honest and sincere expression.

(of a sandwich) Composed of a single slice of bread with a topping.

The characteristic of being open-minded.