protuberance [pr?? to????o?????b??r ??ns, -tyo????o?????-; pr??-]Use protuberance in a sentence noun the condition or fact of being protuberant a part or thing that protrudes; projection; bulge; swellingAlso protuberancy protuberance noun Something, such as a bulge, knob, or swelling, that protrudes.