成长(chéng zhǎng) - to grow up, to mature, to develop in Mandarin

成长 (chéng zhǎng) is growth as a process over time: a child becoming an adult, a person gaining maturity, a business getting bigger year on year. It carries a warm, approving tone, which is why it is everywhere in parenting talk and company reports alike.

It works as a verb and as a noun with no change of form. 他成长得很快 is he is growing fast; 成长的过程 is the process of growing up. 成长故事 is a coming-of-age story.

The trap is the 长. Here it is zhǎng, third tone, meaning to grow, not cháng, second tone, meaning long. Say chéng cháng and you have said nothing at all. For plain physical growth of a plant use 生长 (shēng zhǎng); 成长 is about becoming.