Real Dictionary

pioneer
Someone who is referred to as a pioneer in a particular area of activity is one of the first people to be involved in it and develop it.

pioneer in American English
a member of a military engineer unit trained to construct or demolish bridges, roads, trenches, etc.
being one of the first of its kind
to be a pioneer
to prepare or open (a way, etc.)
noun: a person who is among those who first enter or settle a region, thus opening it for occupation and development by others

pioneer in British English
noun: a colonist, explorer, or settler of a new land, region, etc
noun: a total abstainer from alcoholic drink, esp a member of the Pioneer Total Abstinence Association, a society devoted to abstention
verb: to be a pioneer (in or of)