delegate , n
1. A person sent or deputed to act for or represent another or others; one entrusted with authority or power to be exercised on behalf of those by whom he is appointed; a deputy, commissioner.
delegation , n of action
1. The action of delegating or fact of being delegated; appointment or commission of a person as a delegate or representative; the entrusting of authority to a delegate.

-- Oxford English Dictionary, 2nd edn

Delegation is a mechanism that allows objects to delegate responsibility for performing an operation or finding a value to one or more designated 'ancestors'.

-- Wegner, 1987a