Wiktionary
vb. 1 (context idiomatic English) To become too physically large for something, especially clothes. 2 (context idiomatic by extension English) To become too mature for something.
Usage examples of "grow out of".
Dry sand was about their feet, and under them thin wiry grass, that just managed to grow out of the poverty-stricken shore.
Ever since his son had commenced to grow out of infancy, he had liked his home less and less, till at last he had seemed to dread it.
Some foals do grow out of their problems, so the breeder stuck this one in a far pasture and let him mature.
Powerful things, they live off death, grow out of rot and corruption.
While on either hand arose, as plants might grow out of rich earth, walls, houses, mighty towers, and buildings.
At other times she was convinced he was merely shallow and told herself that he would eventually grow out of his youthful impatience, that time would deepen and perfect him.
But the theatre, the form of entertainment which has become almost a necessary part of our own lives, did not grow out of these recited heroic tales.