"
Rahul" seems to be derived from Rahu, one of the nine planets (Navgraha). When
Gautam Buddha saw his newly born son, he named him
Rahul, meaning "Obstacle", since that was also the night when
Gautama had decided to leave his princely life and go out searching for meaning of life and its sufferings, and his baby son might have caused momentary weakness in his resolve.
It is possible that "
Rahul" may have other meanings as well, like many other Sanskrit terms.