compass

compass — noun

1. a small navigational tool with a magnetised needle that turns freely and lines u

1.nounB1
Definition

a small navigational tool with a magnetised needle that turns freely and lines up with the Earth's magnetic field, showing the direction of north so that you can find your way.

Example

The hiker checked her compass before stepping off the marked trail into the woods.

collocation: check a compass

Before GPS, sailors used a compass and stars to guide ships across oceans.

used in historical contexts

Common collocations
  • magnetic compass
  • compass needle
  • compass point
  • compass direction
  • read a compass
  • use a compass
Synonyms
  • GPS

    a modern electronic device that does the same job using satellites; more common in everyday speech today

  • sextant

    a more complex navigational instrument used with the sun or stars, not for everyday use

Common Mistakes

The compass needle points to the north pole.
The compass needle points to magnetic north, which is slightly different from the true North Pole.
Magnetic north and true north are not the same location.

2. a drawing instrument made of two hinged legs — one with a sharp point and the ot

2.nounB2
Definition

a drawing instrument made of two hinged legs — one with a sharp point and the other holding a pencil — used to create circles or arcs and to compare lengths on a chart.

Example

The geometry teacher asked the class to use a compass to draw a circle.

use a compass + to-infinitive purpose

Priya adjusted the compass arms to match the distance between two cities on the map.

adjusted the arms of the compass

Common collocations
  • pair of compasses
  • drawing compass
  • adjust a compass
  • compass arm
  • compass point (the sharp tip)
Synonyms
  • pair of compasses

    the formal or traditional British name for the same tool

  • divider

    a similar tool used specifically for transferring measurements rather than drawing circles

Usage Note

This tool is often called a 'pair of compasses' in formal or traditional British usage, though 'compass' alone is common in both British and American English.

Common Mistakes

I used a compass to draw a straight line.
I used a ruler to draw a straight line.
A compass draws circles and arcs; a ruler draws straight lines.

3. the range of things that someone or something can affect, achieve, or be involve

3.nounC1
Definition

the range of things that someone or something can affect, achieve, or be involved in — for example, the limit of a person's knowledge, an organisation's authority, or an idea's influence.

Example

Understanding advanced physics is beyond the compass of most high school students without further study.

fixed phrase: beyond the compass of

The charity only works within the compass of helping homeless families.

fixed phrase: within the compass of

Common collocations
  • beyond the compass of
  • within the compass of
  • outside the compass of
Synonyms
  • scope

    the most common and neutral alternative; works in the same fixed phrases and also alone

  • range

    similar meaning, slightly less formal; used in daily contexts such as 'range of abilities'

  • extent

    focuses on how far something reaches, often used in formal or written English

Usage Note

This sense almost always appears in fixed prepositional phrases such as 'beyond the compass of', 'within the compass of', or 'outside the compass of'. It is not used alone as a simple noun (e.g. ❌ 'the compass of the project').

Common Mistakes

The compass of the problem is very large.
The scope of the problem is very large.
'Compass' in this sense is used mostly in fixed phrases like 'beyond the compass of', not as a standalone noun.

compass — verb

Word family

Synonym discussion

Sense: noun/1

These words all describe tools for finding your way, but they differ in technology and context. A 'compass' is a simple magnetic device that points north and requires the user to read a map and interpret the direction — it is the oldest and most basic tool, still used by hikers and scouts. 'GPS' (Global Positioning System) is a modern electronic device that uses satellites to show your exact location on a digital map, giving turn-by-turn directions. 'Sextant' is a specialised navigational instrument used mainly at sea or in the air, measuring the angle between the sun or stars and the horizon — it requires training to use and is rarely seen outside professional navigation. 'Navigator' can refer either to a person who plans a route or to an electronic navigation system in a vehicle. In everyday situations, GPS has largely replaced the compass for most people, but a compass remains the reliable backup when batteries die or signals fail — for example, a sailor might use a sextant for celestial navigation while keeping a magnetic compass as the primary direction-finding tool.

compass ↗GPS ↗sextantnavigator ↗

Common collocations

Nouns

  • compass bearing
  • compass reading
  • compass error

Adverbs

  • due north by compass
  • by compass

Phrases

  • box the compass
  • compass rose
  • points of the compass

Prepositions

  • with a compass
  • by compass

Etymology

LatinFrenchEnglish

The word 'compass' comes from Old French 'compas', meaning 'a circle, a measure, or a pair of compasses', which in turn came from Latin 'compassus', meaning 'a step or a measured pace' (from 'com-' meaning 'together' and 'passus' meaning 'a step'). The sense of a 'measuring instrument' (a pair of compasses for drawing circles) appeared first. By the 14th century, the word was also used for the magnetic direction-finding device, because the instrument's rotating needle seemed to 'measure' or 'step out' the directions. The figurative sense of 'range' or 'scope' developed from the idea of a measured space or limit.