The word Rāvaṇa (Sanskrit: रावण) means roaring opposite of Vaiśravaṇa meaning "hear distinctly" (passive). Both Ravana and Vaiśravaṇa, who is popularly known as Kubera, are considered to be patronymics derived as sons of Vishrava. "Rāvana" was a title taken on later by Dashananda, and it means in Sanskrit, "screamer."
Kumbhakarna is a Sanskrit name for boys meaning Generally good-tempered but huge, ravenous, and powerful.