NOUN (3)

1. pain in muscles or joints sometimes experienced by children and often attributed to rapid growth;

2. emotional distress arising during adolescence;

3. problems that arise in enlarging an enterprise (especially in the early stages);

WordNet (r) 3.0 (2006):

growing pains
    n 1: pain in muscles or joints sometimes experienced by children
         and often attributed to rapid growth
    2: emotional distress arising during adolescence
    3: problems that arise in enlarging an enterprise (especially in
       the early stages)