oscillation

noun

os·​cil·​la·​tion ˌä-sə-ˈlā-shən 

1

: the action or state of oscillating

… stays can be effectively used to prevent oscillations in new bridges …

—D. B. Steinman

2

: variation, fluctuation

… famines due to excessive storminess and violent oscillations of rain and drought, heat and cold.

—Ellsworth Huntington

3

: a flow of electricity changing periodically from a maximum to a minimum

especially : a flow periodically changing direction

4

: a single swing (as of an oscillating body) from one extreme limit to the other

Each oscillation of the pendulum represents one second.

oscillational

ˌä-sə-ˈlā-sh(ə-)nəl 

adjective

Synonyms of oscillation

• fluctuation
• change

Examples of oscillation in a Sentence

the continued oscillation of the fan

There has been oscillation between optimism and pessimism among voters.

Recent Examples on the Web

For instance, light particles like positrons (or electrons, in this experiment) need extremely fast oscillations, gigahertz (GHz) frequencies, to stay confined. —Rupendra Brahambhatt, Interesting Engineering, 11 Apr. 2026

But the oscillation wasn’t happening slowly over millions of miles between the sun and the Earth. —Quanta Magazine, 8 Apr. 2026

European markets’ Tuesday oscillations followed a four-day Easter break, after finishing Thursday’s session in mixed territory. —Hugh Leask,joseph Wilkins, CNBC, 7 Apr. 2026

The oscillations are influenced by the structure of the Sun's interior, which is defined by flows of plasma within the convective layer. —Keith Cooper, Space.com, 26 Mar. 2026

Word History

First Known Use

1658, in the meaning defined at sense 1

Rhymes for oscillation

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Kids Definition

oscillation

noun

os·​cil·​la·​tion ˌäs-ə-ˈlā-shən 

1

: the action or state of oscillating : vibration

2

: variation sense 1, fluctuation

3

: a single swing (as of an oscillating body) from one extreme limit to the other

Medical Definition

oscillation

noun

os·​cil·​la·​tion ˌäs-ə-ˈlā-shən 

1

: the action or state of oscillating

2

: a flow of electricity changing periodically from a maximum to a minimum

especially : a flow periodically changing direction