The mythology behind the name of this place originates from the story of Hareetha Maharishi who did penance and meditation on the banks of river Poorna (Chalakudy River). Lord Mahavishnu impressed by the dedication of the Maharishi and appeared before him at the beginning of Kali Yuga. Lord Vishnu gave some advice to Hareetha Maharshi to overcome the difficulties in Kali Yuga and these pieces of advice are called Thiru Mozhi meaning 'Sacred Words'. Thereafter, this place was named as Thirumozhi kalam - kalam means place. Later Thirumozhikkalam became Thirumoozhikkulam.