pi·o·neer / ˌpīəˈnir/ • n. a person who is among the first to explore or settle a new country or area. ∎  a person who is among the first to research and develop a new area of knowledge or activity: a famous pioneer of birth control. ∎  (in the former USSR and other communist countries) a member of a movement for children below the age of sixteen that aimed to foster communist ideals. ∎  a member of an infantry group preparing roads or terrain for the main body of troops. ∎  (also pioneer species) a plant or animal that establishes itself in an unoccupied area.• v. [tr.] develop or be the first to use or apply (a new method, area of knowledge, or activity): he has pioneered a number of innovative techniques. ∎  open up (a road or terrain) as a pioneer.

Pioneer A series of NASA spacecraft that conducted explorations of the solar system. Pioneer 10, launched on 2 March 1972, was the first spacecraft to leave the solar system, in 1987. Pioneer 11 was launched on 5 April 1973, for Saturn. Pioneer Venus, launched in 1978 to Venus, comprised an orbiter and probes sent to the surface.

pioneer a person who is among the first to explore or settle a new country or area. Recorded from the early 16th century (as a military term denoting a member of the infantry), the word comes ultimately (via French) from Latin pedo, the same base as pawn.

Pioneer is the name of a series of American space probes launched between 1958 and 1973, two of which provided the first clear pictures of Jupiter and Saturn (1973–79).

pioneer soldier going in advance of an army to prepare the way XVI; first or original investigator, etc. XVII. orig. pion(n)er — F. pionnier, OF. paonier, peon(n)ier, f. paon, peon (see PAWN1); the suffix later assim. to -EER1.

Pi·o·neer / ˌpīəˈnir/ a series of American space probes launched between 1958 and 1973, two of which provided the first clear pictures of Jupiter and Saturn (1973–79).