Also found in: Dictionary.
1. To fill something in with growth. Stop plucking your eyebrows and just let them grow in for once.
2. To develop some quality or characteristic to a greater degree. You'll grow in knowledge with every college class you take.
grow in something
1. [for someone] to increase in some quality, such as wisdom, strength, stature, etc. As I got older, I was supposed to grow in wisdom and other good things. Sam grew in strength as he got over the disease.
2. [for a plant] to develop or flourish in something or some place. These plants grow in rich soil with moderate moisture. They will grow well in this soil.
To fill an area by growing extensively within it: We cut down too many of the bushes, but they will grow in again soon.