travel through space in order to visit and explore other worlds

(chiefly science fiction) Hypothetical or fictional travel to the past or the future, typically by means of a machine (a time machine) or a wormhole.

One who engages in time travel.

One who travels together with another. / (US) One who sympathizes with the aims or beliefs of an organization without belonging to it; most often applied to a Communist sympathizer.

A man who travels, often within a certain territory, soliciting orders or selling goods.

expenditure incurred by an employee on account of a journey on official business

plural of time-traveller

(physics) a wave that is not bounded by a given space, but can propagate freely / (physics) a wave in which the vibration is in the direction of propagation; a longitudinal wave

(Britain, Canada) A preprinted cheque for a fixed amount, often in a foreign currency, issued by a bank that may be used instead of cash; may usually be replaced if lost or stolen.

A company that arranges travel and accommodation for travellers.