unmanned

Etymology

From un- + manned.

adj

1. Not operated by a person or a crew.
   In his submission to the UN, [Christof] Heyns points to the experience of drones. Unmanned aerial vehicles were intended initially only for surveillance, and their use for offensive purposes was prohibited, yet once strategists realised their perceived advantages as a means of carrying out targeted killings, all objections were swept out of the way. 2013-06-07, Ed Pilkington, “‘Killer robots’ should be banned in advance, UN told”, in The Guardian Weekly, volume 188, number 26, page 6
   an automated e-mail message sent from an unmanned mailbox
2. Of a bird of prey: not accustomed to the presence of human beings.

verb

1. simple past and past participle of unman