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" Study the Exact Words Examiners Use Audit Your Own Writing for Lexical Resource Explain New Words Out Loud To Yourself Related words TOEFL brighten IELTS startle GRE abide SAT abnormal TOEFL aboard TOEFL abolition IELTS upward TOEFL abort IELTS abortion SAT abrupt SAT absence TOEFL absent