Growth at centre of ritual promotes maturity (6)
I believe the answer is:
tumour
'growth' is the definition.
(I know that tumour is a type of growth)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for tumour that I've seen before include "Abnormal growth in body, may be malignant" , "Abnormal mass growing in the body, may be malignant" , "Cancerous growth in body" , "Abnormal mass of tissue growing in or on the body" .)