TOEFL IELTS periodic Definition Occurring at regular intervals. Example "The patient experiences periodic bouts of dizziness with no clear cause." Sign in to save TOEFL PDF — $25 IELTS PDF — $25 ← period periodical → Study tips featuring "periodic" TOEFL Academic Vocabulary: Study by Topic Boost Your IELTS Writing With Precise Vocabulary Related words TOEFL brighten GRE abash GRE abate GRE abbreviate GRE abbreviation SAT abdicate GRE abduct SAT abet GRE abhor GRE abide SAT abject TOEFL ablaze