TOEFL IELTS plain Definition Simple or ordinary; also, clear and easy to understand. Example "She wore a plain dress without any decorations." Sign in to save TOEFL Quiz → IELTS Quiz → ← plague plainly → Study tips featuring "plain" Audit Your Own Writing to Find Gaps TOEFL Academic Vocabulary: Study by Topic Boost Your IELTS Writing With Precise Vocabulary Related words TOEFL swiftness GRE abash GRE abate GRE abbreviate GRE abbreviation SAT abdicate GRE abduct SAT abet GRE abhor GRE abide SAT abject TOEFL ablaze