periodic

adjective

pe·​ri·​od·​ic ˌpir-ē-ˈä-dik 

1

a

: occurring or recurring at regular intervals

b

: occurring repeatedly from time to time

2

a

: consisting of or containing a series of repeated stages, processes, or digits : cyclic

periodic decimals

a periodic vibration

b

: being a function any value of which recurs at regular intervals

3

: expressed in or characterized by periodic sentences

Synonyms of periodic

• frequent
• regular
• repeated
• periodical
• constant

Examples of periodic in a Sentence

He takes the car in for periodic oil changes.

sent out periodic reminders about the office dress code

Recent Examples on the Web

Real-time tracking cuts costly checks Nuclear facilities currently rely on a combination of instruments, physical security measures, manual sampling and periodic shutdowns to determine how much nuclear material is present and where it is located. — Neetika Walter, Interesting Engineering, 18 Aug. 2026

While Western intelligence agencies have debated periodic reports of Iranian scientists attending North Korean nuclear tests, Pyongyang’s willingness to proliferate nuclear infrastructure elsewhere is beyond doubt. — Charlie Campbell, Time, 17 Aug. 2026

Versions of the periodic orbit problem have circulated—pun intended—since the 18th century. — Sam MacDonald, Scientific American, 14 Aug. 2026

Ukraine has vowed to get Crimea back and carried out periodic drone strikes in recent years, with limited effect. — Greg Myre, NPR, 13 Aug. 2026

Word History

First Known Use

1650, in the meaning defined at sense 1a

Phrases Containing periodic

• periodic acid
• periodic law
• periodic sentence
• periodic table

Rhymes for periodic

• anodic
• helladic
• melodic
• prosodic
• rhapsodic
• spasmodic
• antispasmodic
• aperiodic
• episodic
• modoc
• sodic
• photoperiodic

Kids Definition

periodic

adjective

pe·​ri·​od·​ic ˌpir-ē-ˈäd-ik 

1

: occurring at regular intervals

2

: consisting of or containing a series of repeated stages

periodic vibrations

Medical Definition

periodic

adjective

pe·​ri·​od·​ic ˌpir-ē-ˈäd-ik 

: occurring or recurring at regular intervals

periodic epidemics