Pragmatist
From dKosopedia
In common usage, a pragmatist is someone concerned with results often as opposed to someone regarded as an [ideologue]] or an idealist.
However, in a more saavy sense, a pragmatist is someone who subscribes to some version of pragmatism as a philosophy--be it a general philosophy, a philosophy of science, a political philosophy, a philosophy of art, etc.
Pragmatists in this sense are those who believe that terms (words, concepts, etc.) are defined empirically (by what they refer to in commonly-observable fact) with reference to a particular specified purpose, not by reference to any transcendent truth (ala Plato's forms, for example) which stands above and apart from whatever purpose we may have in mind.
This allows for a plurality of meanings for terms, without suffering confusion--different meanings reflect different purposes. No one purpose is inherently superior to any other in dictating what meaning should prevail.