- This sense of ‘down’ may have originated through metaphorical extension from the adjective sense of ‘down’ meaning ‘being on record,’ such as in the example ‘I have you down for a reservation for two.’ Possibly, the idea of making a physical record for a future event, such as a reservation, came to mean, through the process of metaphor, willing to carry out or agreeing with a proposed future event.
adjective; other word formation type
willing to carry out or agreeing with a proposed idea or course of action
Etymology : ‘Down’ comes from the Old English ‘ofdune’ meaning ‘downwards,’ which came from ‘dune’ meaning ‘from the hill.’ The adjective sense of ‘depressed mentally’ is attested from 1610; however, the adjective sense of ‘being on record’ is not yet etymologically documented, but it has likely been present in the English language for quite some time.
Source : ‘We’re going to go to out to dinner tonight. You down?’ (conversation with a friend, October 2008)
Last modified: 4 December 2008