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Friction

FRIK-shun /ˈfrɪkʃən/

nounB2

formaltechnicalgeneral

The resistance that one surface or object encounters when moving over another.

Friction is a force that opposes motion or attempted motion between surfaces in contact. It can be beneficial (like tire grip) or detrimental (like wear in machinery). There are different types: static friction (prevents motion) and kinetic friction (opposes motion).

The story behind the word. The word 'Friction' comes from the Latin 'frictio', meaning 'a rubbing'. This, in turn, is derived from the verb 'fricare', which means 'to rub'. The concept of rubbing causing resistance or heat has been understood for millennia, and the term entered English in the late 16th century, solidifying its scientific meaning as the force opposing motion between surfaces.

Word relationships

resistance: Friction is a specific type of resistance (between surfaces); resistance is a broader term.
drag: Drag is resistance to motion through a fluid (air or water); friction is resistance between solid surfaces.

lubrication: The act of applying a substance to reduce friction.
smoothness: The quality of having an even, untextured surface, which typically reduces friction.

Commonly confused with

Drag: Friction is between solid surfaces; drag is resistance in fluids.

Word family

frictional (adjective): relating to friction
fricative (noun): a consonant produced by forcing air through a narrow opening

Collocations

reduce friction
static friction
kinetic friction
coefficient of friction
rolling friction

Idioms & expressions

friction of conflict

Example sentences

"The friction between the car's tires and the road allows it to accelerate and brake safely." Explaining a physical force.
"Engineers often try to reduce friction in moving parts of machines to improve efficiency and reduce wear." In engineering.
"Ice greatly reduces the friction on a surface, making it slippery and dangerous for walking." In a natural setting.

Memory hook

Think of 'FRICTION' as the 'FRICTION' between two friends who are rubbing each other the wrong way. Rubbing resistance

When not to use

While 'friction' can metaphorically mean conflict or disagreement (e.g., 'friction between colleagues'), ensure the context is clear when referring to the physical force.

Fun facts

Friction is essential for walking, driving, and gripping objects.
Without friction, objects would continue to slide indefinitely on any surface.

Related words

Force, Motion

Explore more words

discord, clash, dissonance, confrontation, animosity, conflict