level

Concise Oxford English Dictionary © 2008 Oxford University Press:
level/ˈlevl/

▶noun

• 1 a horizontal plane or line with respect to the distance above or below a given point.

• 2 a height or distance from the ground or another base.

  ■ a floor within a multi-storey building.

• 3 a position or stage on a scale of quantity, extent, rank, or quality.

• 4 a flat area of land.

• 5 an instrument giving a line parallel to the plane of the horizon for testing whether things are horizontal.

  ■ Surveying an instrument for giving a horizontal line of sight.

▶adjective

• 1 having a flat, horizontal surface.

  ■ (of a quantity of a dry substance) not rising above the brim of the measure: a level teaspoon of salt.

• 2 at the same height as someone or something else.

• 3 having the same position or value.

• 4 calm and steady: a level voice.

▶verb (levels, levelling, levelled; US levels, leveling, leveled)

• 1 make or become level.

  ■ demolish (a building or town).

• 2 make or become equal or similar.

• 3 aim or direct (a weapon, criticism, or accusation).

• 4 (level with) informal be frank with.

• 5 Surveying ascertain differences in the height of (land).

– phrases
do one's level best make all possible efforts.
level of attainment Brit. a rating of the ability of a school pupil, on a scale of 1 to 10.
be level pegging Brit. be equal in score or achievement during a contest.
a level playing field a situation in which everyone has an equal chance of succeeding.
on the level informal honest; truthful.

– derivatives
levelly adverb,
levelness noun.

– origin ME: from OFr. livel, based on L. libella, dimin. of libra ‘scales, balance’.