Dictionary Definition :
Definition[1]
:
kulaputra
Sanskrit term meaning ‘a nobly born son’ or ‘member of a clan’, a term used frequently in Mahāyāna sūtras to denote lay male devotees, often with the added implication that they are Bodhisattvas. The Pāli equivalent, ‘kulaputta’, is equally common in Pāli sūtras.
Source
:
A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)