IELTS hum Definition To make or produce a low, steady continuous sound. Example "The refrigerator began to hum after it was plugged in." Sign in to save IELTS Quiz → ← hull humane → Study tips featuring "hum" Audit Your Own Writing to Find Gaps Boost Your IELTS Writing With Precise Vocabulary Related words IELTS sincere GRE abide SAT abnormal TOEFL aboard TOEFL abolition TOEFL abort IELTS abortion SAT abrupt SAT absence TOEFL absent GRE absolute TOEFL absolutely