Full Idea
Three-dimensionalist think a thing is somehow 'stretched out' through its location at a given time though not through the period during which it exists, and it is present in its entirety at a moment when it exists though not at a position of its location.
Gist of Idea
3-D says things are stretched in space but not in time, and entire at a time but not at a location
Source
Kit Fine (In Defence of Three-Dimensionalism [2006], p.1)
Book Reference
'Being: Developments in Contemporary Metaphysics', ed/tr. Le Poidevin,R [CUP 2008], p.1
A Reaction
This definition is designed to set up Fine's defence of the 3-D view, by showing that various dubious asymmetries show up if you do not respect the distinctions offered by the 3-D view.