She was 100 and her husband and CPI leader P T Punnoose, a former Lok Sabha member, predeceased her many years ago. She is survived by a son and a daughter.
Rosamma, who celebrated her 100th birth day in May this year, was staying with her son in Salalah.
One of the pioneering women activists of the Communist movement in Kerala, Rosamma was elected to the state Assembly in 1957 from Devicolam in Idukki and from Alappuzha in 1987.
A law graduate, she plunged into activism at a young age as a member of the Travancore State Congress and participated in the freedom struggle. Later, she joined the Communist Party and the split in the movement in 1964, she staunchly stood by the CPI.
She also served as a member of the Kerala Women's Commission, Rubber Board and Chairperson of the Plantation Corporation and Housing Board.