plural of O-level

plural of line of levels

A connected series of measurements, by means of a level, along a given line, such as that of a railroad, to ascertain the profile of the ground.

A spirit level in which a glass-covered box is used instead of a tube.

In a level-headed manner.

(mining) A level or drainage gallery which has a vertical shaft at each end, and acts as an inverted siphon.

plural of split-level

Any of several internationally agreed standard altitudes that are based on atmospheric pressure rather than on true height

(economics) An index of the average market price of selected goods weighted according to certain criteria.

The relative difficulty of completing a task or objective. / (video games) A variable setting in a video game determining how challenging it is to play.