grow /groʊ/ verb 1. to increase by natural development, as any living organism or part by assimilation of nutriment; increase in size or substance. 2. to form and increase in size by a process of inorganic accretion, as by crystallization. 3. to arise or issue as a natural development from an original happening, circumstance, or source: Our friendship grew from common interests. 4. to increase gradually in size, amount, etc.; become greater or larger; expand: His influence has grown. 5. to become gradually attached or united by or as if by growth: The branches of the trees grew together, forming a natural arch. 6. to come to be by degrees; become: to grow old.