The term 'grew mature' can be summarized by two crossword solutions: RIPENED (7 letters) and AGED (4 letters). Ripening is the process of a fruit or vegetable becoming softer, sweeter, and more flavorful as it matures. AGED is a term used to describe something that has been around for a long time and has developed a certain quality due to its age. Both terms can be used to describe the process of something growing older and developing a more mature state.