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Displacement

diss-PLAYSS-ment /dɪsˈpleɪsmənt/

nounC1GRESAT

FormalScientific

The vector quantity that describes the change in position of an object, from its initial to its final position.

Unlike distance, which is a scalar and measures the total path length, displacement is a vector and only considers the straight-line distance and direction from start to end.

The story behind the word. "Displacement" comes from the Old French "desplacer," meaning "to dislodge, remove." This combines the prefix "des-" (meaning "apart" or "away") with "placer" (to place). So, it literally means "to place away" or "to remove from its place," which perfectly describes the change in position.

Word relationships

shift: "Shift" is a general term for a change in position; "displacement" is the precise vector quantity.
relocation: "Relocation" implies moving to a new place, often permanently, less specific to the vector nature of displacement.

fixedness: The state of being stationary or unmoving.
permanence: The state of remaining in one place.

Commonly confused with

Distance: Distance is a scalar (total path length); displacement is a vector (straight line from start to end).

Word family

displace (verb): To move something from its usual place.
displaced (adjective): Moved from its original position.

Collocations

angular displacement
linear displacement
total displacement
calculate displacement
measure displacement

Idioms & expressions

mass displacement (sociology term)

Example sentences

"After walking around the block, her total displacement was zero, even though she covered a significant distance." Explaining a physics concept.
"Displacement is a vector quantity that refers to 'how far out of place' an object is; it is the object's overall change in position." From a scientific definition. (The Physics Classroom)

Memory hook

DISPLACEMENT means an object is DIS-PLACED from its original spot. Dis-Placed

When not to use

Do not confuse "displacement" with "distance." If you walk 5 miles east and 5 miles west, your distance traveled is 10 miles, but your displacement is 0.

Fun facts

Archimedes' principle of buoyancy is often called the 'principle of displacement' because it relates to the volume of fluid displaced by an object.
In navigation, displacement is crucial for calculating a direct route.