English Reference
noun

altitude

n.
US /ˈæɫtəˌtud/ UK /ˈæltɪtjˌuːd/ al·ti·tude UK spelling altitudes

  1. 01 B2 Upper Intermediate

    the height of an object or place above the level of the sea.

    the vertical elevation of an object or location above a given datum, typically mean sea level.

    Simple

    The plane flew at an altitude of 30,000 feet to avoid the storm.

    In context

    At high altitudes, the air becomes significantly thinner, which can lead to hypoxia if climbers do not acclimatise properly before reaching the summit.

    Usage

    Often used with the preposition 'at'.

  2. 02 C1 Advanced Technical Math

    the height of a shape, like a triangle, measured from the bottom to the top point.

    the perpendicular distance from the vertex of a geometric figure to the opposite side or the plane containing the base.

    Simple

    To find the area of the triangle, you must first measure its altitude.

    In context

    The student calculated the area of the scalene triangle by identifying the altitude from the highest vertex to the extended base line.

  3. 03 C2 Proficiency Technical Science

    the angle of a star or planet above the horizon.

    the angular distance of a celestial object above the observer's horizon, measured in degrees.

    Simple

    The navigator measured the altitude of the North Star to find their position.

    In context

    By determining the altitude and azimuth of the celestial body, the researchers were able to pinpoint its exact coordinates in the night sky.

  4. 04 C2 Proficiency Literary

    a very high level of quality, rank, or importance.

    a figurative height of excellence, rank, or superiority.

    Simple

    The poet reached a new altitude of fame after her latest book.

    In context

    Few statesmen have ever achieved such an altitude of moral authority within the international community during their own lifetimes.

On 4 August, an Air India Airbus A320 flying from Phuket to Delhi suddenly lost about 91m (300ft) of altitude, injuring 13 passengers and four crew members.

BBC News· 15 Aug 2026

It comes after one of its planes suddenly lost altitude last week, with a number of passengers injured.

BBC News· 13 Aug 2026

From Middle English, borrowed from Latin altitūdō (“height”), from altus (“high”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin altitūdō
Level B2 · Upper Intermediate
Frequency Frequent
Updated