Grow up is a phrase that is used to encourage someone to become more mature and responsible. The crossword solutions for this term are DEVELOP (7 letters), AGE (3 letters), MATURATE (8 letters), ACTYOURAGE (10 letters), DONTBESONAIVE (13 letters), STOPYOURWHINING (15 letters), and YOURESOJUVENILE (15 letters). These words all suggest that growing up involves developing, aging, maturing, acting responsibly, not being naive, stopping complaining, and recognizing one's own immaturity.