TOEFL IELTS complain Definition To express dissatisfaction or pain about something. Example "Customers began to complain about the poor service." Sign in to save TOEFL PDF — $25 IELTS PDF — $25 ← complacency complaint → Study tips featuring "complain" 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