1.VerbTo become too big in size or too mature in age or outlook to continue to want, need, use, experience, or accept some object, practice, condition, belief, etc.
"Poorer children often have to wear whatever an older sibling has outgrown.; I used to have allergies but I outgrew all of them.; Some people blame God for their troubles, but one must outgrow such notions."
2.VerbTo grow faster or larger than.
"The best adapted plant varieties tend to outgrow those less adapted."